Frost dates · Wyoming
When is the first frost in Casper?
Casper right now
33°FFog
- Today48°F / 38°FClouds
- Tomorrow55°F / 39°FClear skies
- Monday60°F / 45°FClouds
The sky's being coy.
Live from OpenWeatherMap. Alerts from the National Weather Service.
In a typical year, Casper’s first frost comes around September 22 and its last around May 26.
One year in ten the first frost comes as early as September 5, and nine years in ten it has arrived by October 4. One year in ten the last frost is over as early as May 12, and nine years in ten it is over by June 10. Casper averages about 183 nights a year at 32°F or colder, with about 117 frost-free days in between in a typical year. It’s frost season here, and the last frost usually comes around May 26. That makes it the 2nd earliest first frost of the 117 cities we track where it freezes most years.
Last updated
No freeze in the forecast for the next 48 hours.
Casper can still freeze in late May, so its summer is basically a long weekend with good PR.
Live 48-hour check from OpenWeatherMap, refreshed about every half hour. Alerts from the National Weather Service.
Frost dates, early, typical and late years
| Early year (1 in 10) | Typical | Late year (1 in 10) | |
|---|---|---|---|
| First frost | September 5 | September 22 | October 4 |
| Last frost | May 12 | May 26 | June 10 |
A frost date here is a night when the official thermometer reads 32°F or colder. Frost on the ground can show up on clear, calm nights a few degrees milder.
Cities with about the same first frost
- Great Falls, Montana: first frost around September 24
- Missoula, Montana: first frost around September 26
- Bismarck, North Dakota: first frost around September 27
Source: NOAA U.S. Climate Normals, 1991 to 2020, station USW00024089.