Frost dates for Harrison 4nw, NE
At Harrison 4nw, the median last spring frost (32°F) is May 17 and the median first fall frost is Sep 28, for a typical growing season of 132 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 5a.
- May 17Last spring frost (median)50% chance of 32°F after this date
- May 31Safer planting date10% chance of 32°F after this date
- Sep 28First fall frost (median)50% chance of 32°F by this date
- 132 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 17 | May 29 | Jun 14 |
| 32°F | May 5 | May 17 | May 31 |
| 28°F | Apr 24 | May 6 | May 20 |
| 24°F | Apr 10 | 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 5 | Sep 18 | Sep 30 |
| 32°F | Sep 13 | Sep 28 | Oct 11 |
| 28°F | Sep 23 | Oct 5 | Oct 19 |
| 24°F | Sep 30 | Oct 14 | Oct 28 |
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 | 112 days | 129 days |
| 32°F | 113 days | 132 days | 150 days |
| 28°F | 132 days | 151 days | 172 days |
| 24°F | 149 days | 172 days | 193 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 |
|---|---|---|---|
| 69346 | 5a | -20 to -15°F | 17 km |
| 82242 | 5a | -20 to -15°F | 21 km |
| 82225 | 5a | -20 to -15°F | 40 km |
| 69339 | 5a | -20 to -15°F | 43 km |
| 69367 | 5a | -20 to -15°F | 50 km |
| 82219 | 5a | -20 to -15°F | 55 km |
| 69354 | 5a | -20 to -15°F | 60 km |
| 57735 | 4b | -25 to -20°F | 61 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 USC00253617, at 42.7433, -103.9219, elevation 1546 m (5,073 ft).
- Data quality: Representative (10+ years), 12 years of freeze data.
- Average days per year at or below 32°F: 174.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Harrison (7 km)
- Harrison 9ne (13 km)
- Harrison 20 SSE (39 km)
- Fort Robinson (39 km)
- Agate 3 E (39 km)
- Plainsview Rch (63 km)
- Chadron Muni Airport (68 km)
- Chadron 3sw (71 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.