Frost dates for Harrison 9ne, NE
At Harrison 9ne, the median last spring frost (32°F) is May 12 and the median first fall frost is Oct 2, for a typical growing season of 141 days. For a 90% chance that the last frost has passed, wait until May 24. Nearby ZIP codes are in USDA hardiness zones 4b to 5a.
- May 12Last spring frost (median)50% chance of 32°F after this date
- May 24Safer planting date10% chance of 32°F after this date
- Oct 2First fall frost (median)50% chance of 32°F by this date
- 141 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 11 | May 24 | Jun 5 |
| 32°F | May 2 | May 12 | May 24 |
| 28°F | Apr 18 | May 3 | May 15 |
| 24°F | Apr 7 | Apr 23 | May 7 |
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 8 | Sep 23 | Oct 5 |
| 32°F | Sep 16 | Oct 2 | Oct 15 |
| 28°F | Sep 26 | Oct 11 | Oct 25 |
| 24°F | Oct 3 | Oct 20 | Nov 1 |
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 | 99 days | 120 days | 140 days |
| 32°F | 122 days | 141 days | 160 days |
| 28°F | 140 days | 161 days | 180 days |
| 24°F | 158 days | 180 days | 200 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 | 19 km |
| 82242 | 5a | -20 to -15°F | 33 km |
| 69339 | 5a | -20 to -15°F | 37 km |
| 69367 | 5a | -20 to -15°F | 38 km |
| 82225 | 5a | -20 to -15°F | 47 km |
| 57735 | 4b | -25 to -20°F | 54 km |
| 57763 | 5a | -20 to -15°F | 56 km |
| 69354 | 5a | -20 to -15°F | 57 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 USC00253618, at 42.8003, -103.7867, elevation 1228 m (4,029 ft).
- Data quality: Representative (10+ years), 17 years of freeze data.
- Average days per year at or below 32°F: 166.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Harrison 4nw (13 km)
- Harrison (15 km)
- Fort Robinson (30 km)
- Harrison 20 SSE (42 km)
- Agate 3 E (42 km)
- Chadron Muni Airport (57 km)
- Chadron 3sw (60 km)
- Plainsview Rch (64 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.