Frost dates for Redbird, WY
At Redbird, the median last spring frost (32°F) is May 16 and the median first fall frost is Sep 24, for a typical growing season of 130 days. For a 90% chance that the last frost has passed, wait until May 31. Nearby ZIP codes are in USDA hardiness zones 4b to 5b.
- May 16Last spring frost (median)50% chance of 32°F after this date
- May 31Safer planting date10% chance of 32°F after this date
- Sep 24First fall frost (median)50% chance of 32°F by this date
- 130 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 14 | May 28 | Jun 11 |
| 32°F | May 4 | May 16 | May 31 |
| 28°F | Apr 23 | May 6 | May 19 |
| 24°F | Apr 11 | Apr 26 | May 10 |
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 | Sep 1 | Sep 15 | Sep 28 |
| 32°F | Sep 10 | Sep 24 | Oct 5 |
| 28°F | Sep 19 | Oct 2 | Oct 15 |
| 24°F | Sep 28 | Oct 12 | Oct 24 |
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 | 92 days | 110 days | 129 days |
| 32°F | 112 days | 130 days | 148 days |
| 28°F | 129 days | 148 days | 167 days |
| 24°F | 148 days | 167 days | 186 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 |
|---|---|---|---|
| 82222 | 4b | -25 to -20°F | 30 km |
| 82225 | 5a | -20 to -15°F | 32 km |
| 57735 | 4b | -25 to -20°F | 36 km |
| 82701 | 4b | -25 to -20°F | 52 km |
| 57747 | 5a | -20 to -15°F | 64 km |
| 82242 | 5a | -20 to -15°F | 68 km |
| 57773 | 5b | -15 to -10°F | 68 km |
| 82227 | 5a | -20 to -15°F | 69 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 USC00487555, at 43.2450, -104.2881, elevation 1186 m (3,890 ft).
- Data quality: Standard (24+ years of data), 29 years of freeze data.
- Average days per year at or below 32°F: 179.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Lance Creek 11nne (26 km)
- Lusk 25ne (39 km)
- Lusk 2 SW (57 km)
- Dull Center 1se (58 km)
- Rochelle 7ene (63 km)
- Newcastle (68 km)
- Torrington 29n (85 km)
- Glendo 6ne (95 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.