Frost dates for Douglas 1 SE, WY
At Douglas 1 SE, the median last spring frost (32°F) is May 19 and the median first fall frost is Sep 23, for a typical growing season of 126 days. For a 90% chance that the last frost has passed, wait until Jun 2. Nearby ZIP codes are in USDA hardiness zone 5a.
- May 19Last spring frost (median)50% chance of 32°F after this date
- Jun 2Safer planting date10% chance of 32°F after this date
- Sep 23First fall frost (median)50% chance of 32°F by this date
- 126 daysGrowing season (median)between 32°F freezes
Last spring frost dates
The chance that the temperature drops to the threshold after each date.
| Temperature | 90% chance later | 50% chance later | 10% chance later |
|---|---|---|---|
| 36°F | May 19 | Jun 1 | Jun 15 |
| 32°F | May 7 | May 19 | Jun 2 |
| 28°F | Apr 24 | May 7 | May 21 |
| 24°F | Apr 10 | Apr 26 | May 9 |
First fall frost dates
The chance that the temperature has dropped to the threshold by each date.
| Temperature | 10% chance by | 50% chance by | 90% chance by |
|---|---|---|---|
| 36°F | Aug 31 | Sep 13 | Sep 27 |
| 32°F | Sep 10 | Sep 23 | Oct 6 |
| 28°F | Sep 18 | Oct 3 | Oct 16 |
| 24°F | Sep 27 | Oct 13 | Oct 25 |
Growing season length
Days between the last spring and first fall freeze, as the length reached in 9, 5 and 1 out of 10 years.
| Temperature | 9 in 10 years at least | 5 in 10 years at least | 1 in 10 years at least |
|---|---|---|---|
| 36°F | 83 days | 104 days | 123 days |
| 32°F | 107 days | 126 days | 144 days |
| 28°F | 126 days | 147 days | 167 days |
| 24°F | 148 days | 168 days | 189 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 100% |
| 24°F | 100% |
Closest ZIP codes (each is closer to another station)
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 82633 | 5a | -20 to -15°F | 31 km |
| 82229 | 5a | -20 to -15°F | 34 km |
| 82224 | 5a | -20 to -15°F | 37 km |
| 82213 | 5a | -20 to -15°F | 40 km |
| 82637 | 5a | -20 to -15°F | 41 km |
| 82227 | 5a | -20 to -15°F | 52 km |
| 82215 | 5a | -20 to -15°F | 62 km |
| 82636 | 5a | -20 to -15°F | 66 km |
Not the official USDA Plant Hardiness Zone Map. Zones shown here are the values published in the USDA-ARS / Oregon State University PRISM Group 2023 ZIP code tables, shown unaltered. For the official interactive map, visit planthardiness.ars.usda.gov.
About this station
- NOAA station ID USC00482685, at 42.7467, -105.3603, elevation 1484 m (4,870 ft).
- Data quality: Representative (10+ years), 20 years of freeze data.
- Average days per year at or below 32°F: 182.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Douglas Converse Co Airport (6 km)
- Glendo 6ne (44 km)
- Glendo Rsvr Usbr (45 km)
- Double Four Rch (63 km)
- Guernsey Dam #2 (71 km)
- Guernsey 2nw (71 km)
- Lusk 2 SW (72 km)
- Shirley Basin (74 km)
Sources
- NOAA National Centers for Environmental Information, U.S. Climate Normals 1991–2020, annual/seasonal normals by station (version 1.0.1), file dated June 27, 2023; documentation.
- USDA Agricultural Research Service and PRISM Group, Oregon State University, 2023 Plant Hardiness Zone Map ZIP code tables (CONUS, Alaska, Hawaii, Puerto Rico), files dated November 17, 2023. Data © PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed November 1, 2026. Official map: planthardiness.ars.usda.gov.
- U.S. Census Bureau, 2024 Gazetteer ZIP Code Tabulation Areas file, dated August 30, 2024 (ZIP centroids used to find the nearest station).
Freeze dates are 30-year probabilities, not forecasts. Check your local forecast before planting tender plants.