Frost dates for Casselton Agronomy Farm, ND
At Casselton Agronomy Farm, the median last spring frost (32°F) is May 9 and the median first fall frost is Oct 1, for a typical growing season of 143 days. For a 90% chance that the last frost has passed, wait until May 21. Nearby ZIP codes are in USDA hardiness zone 4a.
- May 9Last spring frost (median)50% chance of 32°F after this date
- May 21Safer planting date10% chance of 32°F after this date
- Oct 1First fall frost (median)50% chance of 32°F by this date
- 143 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 4 | May 18 | May 29 |
| 32°F | Apr 25 | May 9 | May 21 |
| 28°F | Apr 12 | Apr 29 | May 13 |
| 24°F | Apr 5 | Apr 18 | May 3 |
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 10 | Sep 22 | Oct 3 |
| 32°F | Sep 17 | Oct 1 | Oct 15 |
| 28°F | Sep 26 | Oct 10 | Oct 24 |
| 24°F | Oct 4 | Oct 21 | Nov 3 |
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 | 108 days | 126 days | 144 days |
| 32°F | 126 days | 143 days | 163 days |
| 28°F | 143 days | 163 days | 183 days |
| 24°F | 161 days | 183 days | 204 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 100% |
| 24°F | 100% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 58059 | 4a | -30 to -25°F | 8 km |
| 58012 | 4a | -30 to -25°F | 9 km |
| 58079 | 4a | -30 to -25°F | 10 km |
| 58002 | 4a | -30 to -25°F | 16 km |
| 58004 | 4a | -30 to -25°F | 17 km |
| 58021 | 4a | -30 to -25°F | 19 km |
| 58007 | 4a | -30 to -25°F | 24 km |
| 58011 | 4a | -30 to -25°F | 24 km |
| 58006 | 4a | -30 to -25°F | 25 km |
| 58052 | 4a | -30 to -25°F | 27 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 USC00321408, at 46.8769, -97.2328, elevation 285 m (935 ft).
- Data quality: Standard (24+ years of data), 30 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
- Fargo Hector Intl Airport (32 km)
- Fargo 3s (34 km)
- Enderlin 2w (42 km)
- Colgate (52 km)
- Mc Leod 3 E (54 km)
- Lisbon (60 km)
- Valley City 3 NNW (60 km)
- Hillsboro 3 N (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.