Yellowstone National Park, Wyoming
Regional Weather Alerts
| 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: | Frost Advisory |
| Area(s): | Kootenai/Cabinet Region |
| Effective: | 2026-05-17 @ 6:01 pm -> 2026-05-18 @ 9:00 am |
| Onset: | 2026-05-18 @ 1:00 am -> 2026-05-18 @ 9:00 am |
| Severity: | Minor |
| Certainty: | Likely |
| Urgency: | Expected |
| Issued By: | NWS Missoula MT on 2026-05-17 @ 6:01 pm |
| Headline: | Frost Advisory issued May 17 at 5:01PM MDT until May 18 at 8:00AM MDT by NWS Missoula MT |
| Description: |
* WHAT...Temperatures between 25 and 34 degrees will result in frost formation. * WHERE...Kootenai/Cabinet Region. * WHEN...From midnight tonight to 8 AM MDT Monday. * IMPACTS...Frost could harm sensitive outdoor vegetation. Sensitive outdoor plants may be killed if left uncovered. * ADDITIONAL DETAILS...Temperature ranges include: 31 to 35 degrees in Eureka, 25 to 28 in Olney, 32 to 36 Libby and Troy areas, 30 to 35 south of Libby to Happys Inn and 26 to 31 Marion and Yaak areas. |
| Alert: | Frost Advisory |
| Area(s): | Lower Clark Fork Region |
| Effective: | 2026-05-17 @ 6:01 pm -> 2026-05-18 @ 9:00 am |
| Onset: | 2026-05-18 @ 1:00 am -> 2026-05-18 @ 9:00 am |
| Severity: | Minor |
| Certainty: | Likely |
| Urgency: | Expected |
| Issued By: | NWS Missoula MT on 2026-05-17 @ 6:01 pm |
| Headline: | Frost Advisory issued May 17 at 5:01PM MDT until May 18 at 8:00AM MDT by NWS Missoula MT |
| Description: |
* WHAT...Temperatures between 25 and 34 degrees will result in frost formation. * WHERE...Lower Clark Fork Region. * WHEN...From midnight tonight to 8 AM MDT Monday. * IMPACTS...Frost could harm sensitive outdoor vegetation. Sensitive outdoor plants may be killed if left uncovered. * ADDITIONAL DETAILS...Temperature ranges include:28 to 32 degrees in Thompson Falls, 30 to 34 degrees in Plains, 33 to 37 degrees in Noxon, 25 to 28 degrees in Haugan, 29 to 32 degrees in St. Regis, and 29 to 34 degrees in Alberton. |
| Alert: | Frost Advisory |
| Area(s): | Flathead/Mission Valleys; Missoula/Bitterroot Valleys |
| Effective: | 2026-05-17 @ 6:01 pm -> 2026-05-18 @ 10:00 am |
| Onset: | 2026-05-17 @ 9:00 pm -> 2026-05-18 @ 10:00 am |
| Severity: | Minor |
| Certainty: | Likely |
| Urgency: | Expected |
| Issued By: | NWS Missoula MT on 2026-05-17 @ 6:01 pm |
| Headline: | Frost Advisory issued May 17 at 5:01PM MDT until May 18 at 9:00AM MDT by NWS Missoula MT |
| Description: |
* WHAT...Temperatures as low as 28 degrees will result in frost formation. * WHERE...Flathead/Mission Valleys and Missoula/Bitterroot Valleys. * WHEN...From 8 PM this evening to 9 AM MDT Monday. * IMPACTS...Frost could harm sensitive outdoor vegetation. Sensitive outdoor plants may be killed if left uncovered. * ADDITIONAL DETAILS...Low-lying areas of the Bitterroot Valley could fall between 24 and 28 degrees. |