Cheyenne, Wyoming

Regional Weather Alerts


     

Alert: Winter Storm Warning
Area(s): East Sweetwater County
Effective: 2026-05-18 @ 4:14 am -> 2026-05-18 @ 7:00 pm
Onset: 2026-05-18 @ 4:14 am -> 2026-05-18 @ 7:00 pm
Severity: Severe
Certainty: Likely
Urgency: Expected
Issued By: NWS Riverton WY on 2026-05-18 @ 4:14 am
Headline: Winter Storm Warning issued May 18 at 3:14AM MDT until May 18 at 6:00PM MDT by NWS Riverton WY
Description: * WHAT...Heavy snow expected. Additional snow accumulations between
4 and 8 inches. Lower amounts up to 2 inches in the Rock Springs
area. Winds gusting as high as 60 mph.

* WHERE...East Sweetwater County.

* WHEN...Until 6 PM MDT this evening.

* IMPACTS...Travel will be very difficult, especially along
Interstate 80 due to the crosswind component. The hazardous
conditions will impact the Monday morning commute.

Alert: Winter Weather Advisory
Area(s): Upper Green River Basin
Effective: 2026-05-18 @ 4:14 am -> 2026-05-18 @ 7:00 pm
Onset: 2026-05-18 @ 4:14 am -> 2026-05-18 @ 7:00 pm
Severity: Moderate
Certainty: Likely
Urgency: Expected
Issued By: NWS Riverton WY on 2026-05-18 @ 4:14 am
Headline: Winter Weather Advisory issued May 18 at 3:14AM MDT until May 18 at 6:00PM MDT by NWS Riverton WY
Description: * WHAT...Snow expected. Total snow accumulations 1 to 3 inches.
Winds gusting as high as 45 mph.

* WHERE...Upper Green River Basin.

* WHEN...Until 6 PM MDT this evening.

* IMPACTS...Travel could be difficult due to a combination of wind
and falling snow. The hazardous conditions could impact the Monday
morning commute.

* ADDITIONAL DETAILS...Greatest impacts will be further south,
towards Farson. Here, winds and snow totals will be greatest.

Alert: Winter Weather Advisory
Area(s): Upper Wind River Basin; Wind River Basin
Effective: 2026-05-18 @ 4:14 am -> 2026-05-18 @ 7:00 pm
Onset: 2026-05-18 @ 4:14 am -> 2026-05-18 @ 7:00 pm
Severity: Moderate
Certainty: Likely
Urgency: Expected
Issued By: NWS Riverton WY on 2026-05-18 @ 4:14 am
Headline: Winter Weather Advisory issued May 18 at 3:14AM MDT until May 18 at 6:00PM MDT by NWS Riverton WY
Description: * WHAT...Snow expected. Additional snow accumulations between 1 and
4 inches, with locally higher amounts are possible around Hudson
and Fort Washakie. Winds gusting as high as 45 mph.

* WHERE...Upper Wind River Basin and Wind River Basin.

* WHEN...Until 6 PM MDT this evening.

* IMPACTS...Travel could be difficult due to a combination of snow
and wind. The hazardous conditions could impact the Monday morning
commute. Where heavy snow occurs, it is possible for tree limbs to
break, as many trees have leafed out.

Alert: Winter Weather Advisory
Area(s): Northeast Johnson County; Southeast Johnson County
Effective: 2026-05-18 @ 4:14 am -> 2026-05-18 @ 7:00 pm
Onset: 2026-05-18 @ 4:14 am -> 2026-05-18 @ 7:00 pm
Severity: Moderate
Certainty: Likely
Urgency: Expected
Issued By: NWS Riverton WY on 2026-05-18 @ 4:14 am
Headline: Winter Weather Advisory issued May 18 at 3:14AM MDT until May 18 at 6:00PM MDT by NWS Riverton WY
Description: * WHAT...Snow expected. Total snow accumulations up to 2 inches.
Winds gusting as high as 35 mph.

* WHERE...Northeast Johnson County and Southeast Johnson County.

* WHEN...Until 6 PM MDT this evening.

* IMPACTS...Travel could be difficult due to a combination of wind
and blowing snow. The hazardous conditions could impact the Monday
morning commute.

* ADDITIONAL DETAILS...Greatest snow totals will occur along the
mountains and further southwards towards Kaycee.

Alert: Winter Weather Advisory
Area(s): South Lincoln County
Effective: 2026-05-18 @ 4:14 am -> 2026-05-18 @ 7:00 pm
Onset: 2026-05-18 @ 4:14 am -> 2026-05-18 @ 7:00 pm
Severity: Moderate
Certainty: Likely
Urgency: Expected
Issued By: NWS Riverton WY on 2026-05-18 @ 4:14 am
Headline: Winter Weather Advisory issued May 18 at 3:14AM MDT until May 18 at 6:00PM MDT by NWS Riverton WY
Description: * WHAT...Snow expected. Additional snow accumulations between 1 and
3 inches. Winds gusting as high as 40 mph.

* WHERE...South Lincoln County.

* WHEN...Until 6 PM MDT this evening.

* IMPACTS...Travel could be difficult. The hazardous conditions
could impact the Monday morning commute.

Alert: Winter Weather Advisory
Area(s): Cody Foothills; Southwest Bighorn Basin
Effective: 2026-05-18 @ 4:14 am -> 2026-05-18 @ 7:00 pm
Onset: 2026-05-18 @ 4:14 am -> 2026-05-18 @ 7:00 pm
Severity: Moderate
Certainty: Likely
Urgency: Expected
Issued By: NWS Riverton WY on 2026-05-18 @ 4:14 am
Headline: Winter Weather Advisory issued May 18 at 3:14AM MDT until May 18 at 6:00PM MDT by NWS Riverton WY
Description: * WHAT...Snow expected. Total snow accumulations up to 2 inches.
Winds gusting as high as 50 mph.

* WHERE...Southwest Bighorn Basin and Cody Foothills.

* WHEN...Until 6 PM MDT this evening.

* IMPACTS...Travel could be difficult due to a combination of snow
and wind. The hazardous conditions could impact the Monday morning
commute.

* ADDITIONAL DETAILS...There is potential for a steep gradient in
snow totals along the mountains, with snow totals quickly going
from around 1 inch to 4 inches or more.

Alert: Winter Storm Warning
Area(s): Wind River Mountains East
Effective: 2026-05-18 @ 4:14 am -> 2026-05-18 @ 7:00 pm
Onset: 2026-05-18 @ 4:14 am -> 2026-05-18 @ 7:00 pm
Severity: Severe
Certainty: Likely
Urgency: Expected
Issued By: NWS Riverton WY on 2026-05-18 @ 4:14 am
Headline: Winter Storm Warning issued May 18 at 3:14AM MDT until May 18 at 6:00PM MDT by NWS Riverton WY
Description: * WHAT...Heavy snow expected. Additional snow accumulations between
5 and 9 inches, with locally higher amounts at the highest
elevations. Winds gusting as high as 60 mph.

* WHERE...Wind River Mountains East.

* WHEN...Until 6 PM MDT this evening.

* IMPACTS...Travel could be very difficult. The hazardous conditions
could impact the Monday morning commute, including over South Pass.

Alert: Winter Storm Warning
Area(s): Natrona County Lower Elevations
Effective: 2026-05-18 @ 4:14 am -> 2026-05-18 @ 7:00 pm
Onset: 2026-05-18 @ 4:14 am -> 2026-05-18 @ 7:00 pm
Severity: Severe
Certainty: Likely
Urgency: Expected
Issued By: NWS Riverton WY on 2026-05-18 @ 4:14 am
Headline: Winter Storm Warning issued May 18 at 3:14AM MDT until May 18 at 6:00PM MDT by NWS Riverton WY
Description: * WHAT...Heavy snow expected. Total snow accumulations between 3 and
6 inches. Areas of higher amounts up to 8 inches between Hiland
and Casper and the south side of Casper. Winds gusting as high as
40 mph.

* WHERE...Natrona County Lower Elevations.

* WHEN...Until 6 PM MDT this evening.

* IMPACTS...Travel will be difficult, especially along US Highway
20/26 between Hiland and Casper. The hazardous conditions will
impact the Monday morning commute. Heavy snow could break tree
limbs as many trees have leafed out.

Alert: Winter Storm Warning
Area(s): Green Mountains and Rattlesnake Range
Effective: 2026-05-18 @ 4:14 am -> 2026-05-18 @ 7:00 pm
Onset: 2026-05-18 @ 4:14 am -> 2026-05-18 @ 7:00 pm
Severity: Severe
Certainty: Likely
Urgency: Expected
Issued By: NWS Riverton WY on 2026-05-18 @ 4:14 am
Headline: Winter Storm Warning issued May 18 at 3:14AM MDT until May 18 at 6:00PM MDT by NWS Riverton WY
Description: * WHAT...Heavy snow possible. Additional snow accumulations between
6 and 12 inches possible with locally higher amounts up to 15
inches. Winds gusting as high as 55 mph.

* WHERE...Green Mountains and Rattlesnake Range.

* WHEN...Until 6 PM MDT this evening.

* IMPACTS...Travel will be difficult. The hazardous conditions will
impact the Monday morning commute.

Alert: Winter Weather Advisory
Area(s): Rock Springs and Green River; Flaming Gorge
Effective: 2026-05-18 @ 4:14 am -> 2026-05-18 @ 7:00 pm
Onset: 2026-05-18 @ 4:14 am -> 2026-05-18 @ 7:00 pm
Severity: Moderate
Certainty: Likely
Urgency: Expected
Issued By: NWS Riverton WY on 2026-05-18 @ 4:14 am
Headline: Winter Weather Advisory issued May 18 at 3:14AM MDT until May 18 at 6:00PM MDT by NWS Riverton WY
Description: * WHAT...Snow expected. Additional snow accumulations between 2 and
5 inches. Winds gusting as high as 55 mph.

* WHERE...Flaming Gorge and Rock Springs and Green River.

* WHEN...Until 6 PM MDT this evening.

* IMPACTS...Travel could be difficult, especially along Interstate
80. The hazardous conditions could impact the Monday morning
commute.

Alert: Winter Weather Advisory
Area(s): Absaroka Mountains; Owl Creek and Bridger Mountains; Bighorn Mountains West; Bighorn Mountains Southeast
Effective: 2026-05-18 @ 4:14 am -> 2026-05-18 @ 7:00 pm
Onset: 2026-05-18 @ 4:14 am -> 2026-05-18 @ 7:00 pm
Severity: Moderate
Certainty: Likely
Urgency: Expected
Issued By: NWS Riverton WY on 2026-05-18 @ 4:14 am
Headline: Winter Weather Advisory issued May 18 at 3:14AM MDT until May 18 at 6:00PM MDT by NWS Riverton WY
Description: * WHAT...Snow expected. Additional snow accumulations up to 6
inches, with the higher amounts expected over southern end of the
Bighorn Mountains. Winds gusting as high as 50 mph.

* WHERE...Owl Creek and Bridger Mountains, Bighorn Mountains
Southeast, Bighorn Mountains West, and Absaroka Mountains.

* WHEN...Until 6 PM MDT this evening.

* IMPACTS...Travel could be difficult, especially over mountain
passes such as Powder River Pass.

Alert: Winter Storm Warning
Area(s): Lander Foothills
Effective: 2026-05-18 @ 4:14 am -> 2026-05-18 @ 7:00 pm
Onset: 2026-05-18 @ 4:14 am -> 2026-05-18 @ 7:00 pm
Severity: Severe
Certainty: Likely
Urgency: Expected
Issued By: NWS Riverton WY on 2026-05-18 @ 4:14 am
Headline: Winter Storm Warning issued May 18 at 3:14AM MDT until May 18 at 6:00PM MDT by NWS Riverton WY
Description: * WHAT...Snow expected. Additional snow accumulations between 5 and
8 inches, with higher amounts near Sinks Canyon Park.

* WHERE...Lander Foothills.

* WHEN...Until 6 PM MDT this evening.

* IMPACTS...Travel could be difficult. The hazardous conditions
could impact the Monday morning commute. Heavy snow could break
tree limbs as many trees have leafed out.

Alert: Winter Storm Warning
Area(s): Casper Mountain
Effective: 2026-05-18 @ 4:14 am -> 2026-05-18 @ 7:00 pm
Onset: 2026-05-18 @ 4:14 am -> 2026-05-18 @ 7:00 pm
Severity: Severe
Certainty: Likely
Urgency: Expected
Issued By: NWS Riverton WY on 2026-05-18 @ 4:14 am
Headline: Winter Storm Warning issued May 18 at 3:14AM MDT until May 18 at 6:00PM MDT by NWS Riverton WY
Description: * WHAT...Heavy snow possible. Additional snow accumulations between
6 and 12 inches possible. Winds could gust as high as 40 mph.

* WHERE...Casper Mountain.

* WHEN...Until 6 PM MDT this evening.

* IMPACTS...Travel could be very difficult. Areas of blowing snow
could significantly reduce visibility. The hazardous conditions
could impact the Monday morning commute. Heavy snow could break
tree limbs as many trees have leafed out.

Alert: Winter Weather Advisory
Area(s): Wind River Mountains West
Effective: 2026-05-18 @ 4:14 am -> 2026-05-18 @ 7:00 pm
Onset: 2026-05-18 @ 4:14 am -> 2026-05-18 @ 7:00 pm
Severity: Moderate
Certainty: Likely
Urgency: Expected
Issued By: NWS Riverton WY on 2026-05-18 @ 4:14 am
Headline: Winter Weather Advisory issued May 18 at 3:14AM MDT until May 18 at 6:00PM MDT by NWS Riverton WY
Description: * WHAT...Snow expected. Additional snow accumulations between 4 and
8 inches. Winds gusting as high as 60 mph.

* WHERE...Wind River Mountains West.

* WHEN...Until 6 PM MDT this evening.

* IMPACTS...Travel could be difficult, especially along South Pass.
The hazardous conditions could impact the Monday morning commute.

Alert: Winter Weather Advisory
Area(s): Pryor/Northern Bighorn Mountains; Northeast Bighorn Mountains
Effective: 2026-05-18 @ 3:06 am -> 2026-05-18 @ 1:00 pm
Onset: 2026-05-18 @ 3:06 am -> 2026-05-18 @ 1:00 pm
Severity: Moderate
Certainty: Likely
Urgency: Expected
Issued By: NWS Billings MT on 2026-05-18 @ 3:06 am
Headline: Winter Weather Advisory issued May 18 at 2:06AM MDT until May 18 at 12:00PM MDT by NWS Billings MT
Description: * WHAT...Snow and blowing snow. Total snow accumulations between 3
and 6 inches, greatest in the Bighorn Mountains. Winds gusting as
high as 45 mph.

* WHERE...In Montana, Pryor/Northern Bighorn Mountains. In Wyoming,
Northeast Bighorn Mountains.

* WHEN...Until noon MDT today.

* IMPACTS...Snow and blowing snow will impact back country recreation
and travel along Highway 14 through the Bighorn Mountains.

Alert: Winter Storm Warning
Area(s): Sierra Madre Range
Effective: 2026-05-18 @ 2:31 am -> 2026-05-18 @ 5:00 pm
Onset: 2026-05-18 @ 2:31 am -> 2026-05-18 @ 7:00 pm
Severity: Severe
Certainty: Likely
Urgency: Expected
Issued By: NWS Cheyenne WY on 2026-05-18 @ 2:31 am
Headline: Winter Storm Warning issued May 18 at 1:31AM MDT until May 18 at 6:00PM MDT by NWS Cheyenne WY
Description: * WHAT...Heavy snow expected. Total snow accumulation 8 to 16
inches, mainly on the eastern side of the Range. Winds gusting as
high as 50 mph with periods of blowing and drifting snow.

* WHERE...Sierra Madre Range.

* WHEN...Until 6 PM MDT this evening.

* IMPACTS...Travel could be very difficult to impossible. The
hazardous conditions could impact the Monday morning and evening
commutes. Strong winds could cause tree damage.

* ADDITIONAL DETAILS...North to northeast facing slopes and ridges
will see the highest accumulations, with accumulations much lower
on the western side of the range near Dixon and Baggs.

Alert: Winter Weather Advisory
Area(s): Converse County Lower Elevations; Shirley Basin; Central Laramie Range and Southwest Platte County; South Laramie Range Foothills
Effective: 2026-05-18 @ 2:31 am -> 2026-05-18 @ 5:00 pm
Onset: 2026-05-18 @ 2:31 am -> 2026-05-18 @ 7:00 pm
Severity: Moderate
Certainty: Likely
Urgency: Expected
Issued By: NWS Cheyenne WY on 2026-05-18 @ 2:31 am
Headline: Winter Weather Advisory issued May 18 at 1:31AM MDT until May 18 at 6:00PM MDT by NWS Cheyenne WY
Description: * WHAT...Snow expected. Total snow accumulations 2 to 6 inches.
Winds gusting as high as 35 mph.

* WHERE...Converse County Lower Elevations, Shirley Basin, Central
Laramie Range and Southwest Platte County, and South Laramie Range
Foothills.

* WHEN...Until 6 PM MDT this evening.

* IMPACTS...Travel could be very difficult. The hazardous conditions
could impact the Monday morning and evening commutes.

Alert: Winter Storm Warning
Area(s): South Laramie Range
Effective: 2026-05-18 @ 2:31 am -> 2026-05-18 @ 5:00 pm
Onset: 2026-05-18 @ 2:31 am -> 2026-05-18 @ 7:00 pm
Severity: Severe
Certainty: Likely
Urgency: Expected
Issued By: NWS Cheyenne WY on 2026-05-18 @ 2:31 am
Headline: Winter Storm Warning issued May 18 at 1:31AM MDT until May 18 at 6:00PM MDT by NWS Cheyenne WY
Description: * WHAT...Heavy snow. Total snow accumulations 7 to 14 inches
expected with locally higher amounts. Winds could gust as high as
30 to 40 mph with some drifting snow expected.

* WHERE...South Laramie Range including the Interstate 80 Summit
between Cheyenne and Laramie.

* WHEN...Until 6 PM MDT this evening.

* IMPACTS...Roads, and especially bridges and overpasses, will
likely become slick and hazardous.

Alert: Winter Storm Warning
Area(s): North Laramie Range; Snowy Range
Effective: 2026-05-18 @ 2:31 am -> 2026-05-18 @ 5:00 pm
Onset: 2026-05-18 @ 2:31 am -> 2026-05-18 @ 7:00 pm
Severity: Severe
Certainty: Likely
Urgency: Expected
Issued By: NWS Cheyenne WY on 2026-05-18 @ 2:31 am
Headline: Winter Storm Warning issued May 18 at 1:31AM MDT until May 18 at 6:00PM MDT by NWS Cheyenne WY
Description: * WHAT...Heavy snow. Total snow accumulations 10 to 20 inches
expected with locally higher amounts possible. Winds could gust as
high as 30 to 40 mph with periods of blowing and drifting snow,
especially above 8500 feet.

* WHERE...Snowy Range and North Laramie Range.

* WHEN...Until 6 PM MDT this evening.

* IMPACTS...Heavy wet snow. Roads, and especially bridges, will
likely become slick and hazardous.

Alert: Winter Storm Warning
Area(s): Central Carbon County
Effective: 2026-05-18 @ 2:31 am -> 2026-05-18 @ 5:00 pm
Onset: 2026-05-18 @ 2:31 am -> 2026-05-18 @ 7:00 pm
Severity: Severe
Certainty: Likely
Urgency: Expected
Issued By: NWS Cheyenne WY on 2026-05-18 @ 2:31 am
Headline: Winter Storm Warning issued May 18 at 1:31AM MDT until May 18 at 6:00PM MDT by NWS Cheyenne WY
Description: * WHAT...Heavy snow and periods of blowing snow. Total snow
accumulations 5 to 10 inches expected with locally higher amounts
near the mountains. Winds could gust as high as 45 mph.

* WHERE...Central Carbon County.

* WHEN...Until 6 PM MDT this evening.

* IMPACTS...Visibilities may drop below 1/4 mile due to falling and
blowing snow.

Alert: Winter Weather Advisory
Area(s): Southwest Carbon County
Effective: 2026-05-18 @ 2:31 am -> 2026-05-18 @ 5:00 pm
Onset: 2026-05-18 @ 2:31 am -> 2026-05-18 @ 7:00 pm
Severity: Moderate
Certainty: Likely
Urgency: Expected
Issued By: NWS Cheyenne WY on 2026-05-18 @ 2:31 am
Headline: Winter Weather Advisory issued May 18 at 1:31AM MDT until May 18 at 6:00PM MDT by NWS Cheyenne WY
Description: * WHAT...Snow and periods of blowing snow. Total snow accumulations
3 to 6 inches, locally heavier in the northern extent of the zone.
Winds gusting as high as 50 mph.

* WHERE...Southwest Carbon County.

* WHEN...Until 6 PM MDT this evening.

* IMPACTS...Travel could be very difficult. The hazardous conditions
could impact the Monday morning and evening commutes. Strong winds
could cause tree damage.

Alert: Winter Storm Warning
Area(s): Ferris/Seminoe/Shirley Mountains; North Snowy Range Foothills
Effective: 2026-05-18 @ 2:31 am -> 2026-05-18 @ 5:00 pm
Onset: 2026-05-18 @ 2:31 am -> 2026-05-18 @ 7:00 pm
Severity: Severe
Certainty: Likely
Urgency: Expected
Issued By: NWS Cheyenne WY on 2026-05-18 @ 2:31 am
Headline: Winter Storm Warning issued May 18 at 1:31AM MDT until May 18 at 6:00PM MDT by NWS Cheyenne WY
Description: * WHAT...Heavy snow and periods of drifting snow. Total snow
accumulations 6 to 12 inches with higher amounts near the
mountains. Winds could gust as high as 35 to 45 mph with periods
of blowing and drifting snow.

* WHERE...North Snowy Range Foothills including Arlington and Elk
Mountain along Interstate 80, and Ferris/Seminoe/Shirley Mountains.

* WHEN...Until 6 PM MDT this evening.

* IMPACTS...Roads, and especially bridges and overpasses, will
likely become slick and hazardous. Scattered power outages
possible due to heavy wet snow on trees and powerlines.

Alert: Winter Weather Advisory
Area(s): Laramie Valley
Effective: 2026-05-18 @ 2:31 am -> 2026-05-18 @ 5:00 pm
Onset: 2026-05-18 @ 2:31 am -> 2026-05-18 @ 7:00 pm
Severity: Moderate
Certainty: Likely
Urgency: Expected
Issued By: NWS Cheyenne WY on 2026-05-18 @ 2:31 am
Headline: Winter Weather Advisory issued May 18 at 1:31AM MDT until May 18 at 6:00PM MDT by NWS Cheyenne WY
Description: * WHAT...Snow and blowing snow expected. Total snow accumulations
between 2 to 6 inches. Winds gusting as high as 35 mph.

* WHERE...Laramie Valley.

* WHEN...Until 6 PM MDT this evening.

* IMPACTS...Travel could be very difficult. The hazardous conditions
could impact the Monday morning and evening commutes.

* ADDITIONAL DETAILS...Portions of the Laramie Valley including
Laramie itself could see amounts on the lower end due to westerly
winds, but portions of the Valley including I-80 may see on the
higher end of these amounts.

Alert: Freeze Watch
Area(s): Ferris/Seminoe/Shirley Mountains; Shirley Basin; Central Carbon County; North Snowy Range Foothills; Southwest Carbon County
Effective: 2026-05-18 @ 2:15 am -> 2026-05-18 @ 5:30 pm
Onset: 2026-05-18 @ 10:00 pm -> 2026-05-19 @ 11:00 am
Severity: Severe
Certainty: Possible
Urgency: Future
Issued By: NWS Cheyenne WY on 2026-05-18 @ 2:15 am
Headline: Freeze Watch issued May 18 at 1:15AM MDT until May 19 at 10:00AM MDT by NWS Cheyenne WY
Description: * WHAT...Sub-freezing temperatures as low as 15 possible.

* WHERE...Central Carbon County, Ferris/Seminoe/Shirley Mountains,
North Snowy Range Foothills, Shirley Basin, and Southwest Carbon
County.

* WHEN...From this evening through Tuesday morning.

* IMPACTS...Frost and freeze conditions could kill crops, other
sensitive vegetation and possibly damage unprotected outdoor
plumbing.

Alert: Freeze Warning
Area(s): Niobrara County
Effective: 2026-05-18 @ 2:15 am -> 2026-05-18 @ 5:30 pm
Onset: 2026-05-18 @ 9:00 pm -> 2026-05-19 @ 11:00 am
Severity: Moderate
Certainty: Likely
Urgency: Expected
Issued By: NWS Cheyenne WY on 2026-05-18 @ 2:15 am
Headline: Freeze Warning issued May 18 at 1:15AM MDT until May 19 at 10:00AM MDT by NWS Cheyenne WY
Description: * WHAT...For the Freeze Warning early this morning, sub-freezing
temperatures as low as 26 expected. For the Freeze Warning
tomorrow night, sub-freezing temperatures as low as 22 possible.

* WHERE...Niobrara County.

* WHEN...For the first Freeze Warning, from 5 AM to 10 AM MDT this
morning. For the second Freeze Warning, from 8 PM this evening to
10 AM MDT Tuesday.

* IMPACTS...Frost and freeze conditions could kill crops, other
sensitive vegetation and possibly damage unprotected outdoor
plumbing.

Alert: Freeze Warning
Area(s): Scotts Bluff; North Sioux; South Sioux; Converse County Lower Elevations; East Platte County; Goshen County
Effective: 2026-05-18 @ 2:15 am -> 2026-05-18 @ 5:30 pm
Onset: 2026-05-18 @ 9:00 pm -> 2026-05-19 @ 11:00 am
Severity: Moderate
Certainty: Likely
Urgency: Expected
Issued By: NWS Cheyenne WY on 2026-05-18 @ 2:15 am
Headline: Freeze Warning issued May 18 at 1:15AM MDT until May 19 at 10:00AM MDT by NWS Cheyenne WY
Description: * WHAT...Sub-freezing temperatures as low as 21 expected.

* WHERE...Portions of the panhandle of Nebraska, and east central
and southeast Wyoming.

* WHEN...From 8 PM this evening to 10 AM MDT Tuesday.

* IMPACTS...Frost and freeze conditions could kill crops, other
sensitive vegetation and possibly damage unprotected outdoor
plumbing.

Alert: Freeze Watch
Area(s): Dawes; Box Butte; Banner; Morrill; Kimball; Cheyenne; Central Laramie Range and Southwest Platte County; Upper North Platte River Basin; Laramie Valley; South Laramie Range; South Laramie Range Foothills; Central Laramie County; East Laramie County
Effective: 2026-05-18 @ 2:15 am -> 2026-05-18 @ 5:30 pm
Onset: 2026-05-19 @ 1:00 am -> 2026-05-19 @ 11:00 am
Severity: Severe
Certainty: Possible
Urgency: Future
Issued By: NWS Cheyenne WY on 2026-05-18 @ 2:15 am
Headline: Freeze Watch issued May 18 at 1:15AM MDT until May 19 at 10:00AM MDT by NWS Cheyenne WY
Description: * WHAT...Sub-freezing temperatures as low as 16 possible.

* WHERE...Portions of panhandle Nebraska and south central and
southeast Wyoming.

* WHEN...From late tonight through Tuesday morning.

* IMPACTS...Frost and freeze conditions could kill crops, other
sensitive vegetation and possibly damage unprotected outdoor
plumbing.

Alert: Freeze Warning
Area(s): Niobrara County
Effective: 2026-05-18 @ 2:15 am -> 2026-05-18 @ 5:30 pm
Onset: 2026-05-18 @ 6:00 am -> 2026-05-18 @ 11:00 am
Severity: Moderate
Certainty: Likely
Urgency: Expected
Issued By: NWS Cheyenne WY on 2026-05-18 @ 2:15 am
Headline: Freeze Warning issued May 18 at 1:15AM MDT until May 18 at 10:00AM MDT by NWS Cheyenne WY
Description: * WHAT...For the Freeze Warning early this morning, sub-freezing
temperatures as low as 26 expected. For the Freeze Warning
tomorrow night, sub-freezing temperatures as low as 22 possible.

* WHERE...Niobrara County.

* WHEN...For the first Freeze Warning, from 5 AM to 10 AM MDT this
morning. For the second Freeze Warning, from 8 PM this evening to
10 AM MDT Tuesday.

* IMPACTS...Frost and freeze conditions could kill crops, other
sensitive vegetation and possibly damage unprotected outdoor
plumbing.

Alert: Freeze Warning
Area(s): Northern Campbell; Southern Campbell; Western Crook; Weston County Plains; Newcastle; Northeastern Crook
Effective: 2026-05-17 @ 11:56 pm -> 2026-05-18 @ 11:00 am
Onset: 2026-05-18 @ 6:00 am -> 2026-05-18 @ 11:00 am
Severity: Moderate
Certainty: Likely
Urgency: Expected
Issued By: NWS Rapid City SD on 2026-05-17 @ 11:56 pm
Headline: Freeze Warning issued May 17 at 10:56PM MDT until May 18 at 10:00AM MDT by NWS Rapid City SD
Description: * WHAT...Sub-freezing temperatures as low as 29 expected.

* WHERE...A portion of northeast Wyoming.

* WHEN...From 5 AM to 10 AM MDT Monday.

* IMPACTS...Frost and freeze conditions could kill crops, other
sensitive vegetation and possibly damage unprotected outdoor
plumbing.

Alert: Winter Weather Advisory
Area(s): Western Uinta Mountains; Southwest Wyoming
Effective: 2026-05-17 @ 11:08 pm -> 2026-05-18 @ 2:15 pm
Onset: 2026-05-17 @ 11:08 pm -> 2026-05-19 @ 1:00 am
Severity: Moderate
Certainty: Likely
Urgency: Expected
Issued By: NWS Salt Lake City UT on 2026-05-17 @ 11:08 pm
Headline: Winter Weather Advisory issued May 17 at 10:08PM MDT until May 19 at 12:00AM MDT by NWS Salt Lake City UT
Description: * WHAT...Snow expected. Total snow accumulations of 6 to 14 inches
for the Western Uinta Mountains with locally higher amounts
further east into the Uinta mountains, and 2 to 6 inches for
southwest Wyoming with locally in excess of 10 inches closer to
the north slopes of the Uintas.

* WHERE...In Utah, Western Uinta Mountains. In Wyoming, Southwest
Wyoming.

* WHEN...Until midnight MDT Monday Night.

* IMPACTS...Travel could be difficult at times. Traction law
restrictions may be enacted.