Frost Dates for Thermopolis 9ne, WY
Elevation: 1305 m
Frost Dates
Last Spring Frost (50%) A 50% chance that the last spring frost has already passed by this date. Most gardeners use this as their primary planting guide.
May 24
First Fall Frost (50%) A 50% chance that the first fall frost has occurred by this date. Plan to harvest or protect tender plants before this date.
September 16
30% Probability
Only a 30% chance of frost remaining by this date. Use these dates for a safer planting window, especially for tender plants sensitive to cold.
Last Spring Frost
May 31
First Fall Frost
September 11
Hard Freeze (28°F)
Last Spring Hard Freeze
May 11
First Fall Hard Freeze
September 24
Growing Season
115 Days
May 24 to September 16
USDA Hardiness Zone
Hardiness zones indicate which perennial plants can survive winter in your area. For annual vegetables, frost dates and growing season length matter more than hardiness zone.Zone 3b
Avg. annual minimum: −35 to −30°F
Köppen Climate
The Köppen climate classification system categorizes climates based on temperature and precipitation patterns.
BSk
Cold Semi-Arid (Steppe)
Cool to cold with low rainfall and wide temperature swings. Common in the western Great Plains and central Asia. Short growing seasons benefit from season extension techniques.
Temperature
-10°
20°
50°
80°
Avg High
Avg Temp
Avg Low
Light Frost (32°F)
Hard Frost (28°F)
Temperature table
| Month | Avg High | Avg Temp | Avg Low |
|---|---|---|---|
| January | 31° | 16° | 0° |
| February | 38° | 23° | 8° |
| March | 50° | 34° | 19° |
| April | 59° | 43° | 27° |
| May | 68° | 52° | 37° |
| June | 78° | 62° | 45° |
| July | 88° | 69° | 51° |
| August | 86° | 67° | 48° |
| September | 75° | 56° | 38° |
| October | 60° | 43° | 26° |
| November | 46° | 30° | 14° |
| December | 32° | 16° | 0° |
Precipitation
0"
1"
2"
3"
3.8"
Precipitation table
| Month | Precipitation |
|---|---|
| January | 2.1 |
| February | 2.3 |
| March | 2.9 |
| April | 3.5 |
| May | 3.8 |
| June | 3.0 |
| July | 2.5 |
| August | 2.5 |
| September | 3.2 |
| October | 3.1 |
| November | 2.6 |
| December | 2.3 |
Sunrise / Sunset
Daylight
Longest: 15h 16m · Shortest: 8h 44m
Sunrise and sunset table
| Month | Sunrise | Sunset | Daylight |
|---|---|---|---|
| January | 7:28 AM | 4:32 PM | 9h 05m |
| February | 6:52 AM | 5:08 PM | 10h 15m |
| March | 6:11 AM | 5:49 PM | 11h 38m |
| April | 5:23 AM | 6:37 PM | 13h 13m |
| May | 4:44 AM | 7:16 PM | 14h 32m |
| June | 4:23 AM | 7:37 PM | 15h 15m |
| July | 4:31 AM | 7:29 PM | 14h 57m |
| August | 5:06 AM | 6:54 PM | 13h 49m |
| September | 5:52 AM | 6:08 PM | 12h 17m |
| October | 6:37 AM | 5:23 PM | 10h 45m |
| November | 7:18 AM | 4:42 PM | 9h 25m |
| December | 7:38 AM | 4:22 PM | 8h 45m |
Nearby Stations
Plan Your Garden with Planter
Now that you know your frost dates, use Planter to plan your veggie garden! Planter is an easy drag-and-drop garden planner with personalized planting schedules.
Try Planter For FreeAvailable everywhere: iOS, Android, web, and more!
