Frost dates for Garrison, ND
At Garrison, the median last spring frost (32°F) is May 12 and the median first fall frost is Sep 30, for a typical growing season of 140 days. For a 90% chance that the last frost has passed, wait until May 24. Nearby ZIP codes are in USDA hardiness zone 4a.
- May 12Last spring frost (median)50% chance of 32°F after this date
- May 24Safer planting date10% chance of 32°F after this date
- Sep 30First fall frost (median)50% chance of 32°F by this date
- 140 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 9 | May 21 | Jun 1 |
| 32°F | Apr 30 | May 12 | May 24 |
| 28°F | Apr 18 | May 2 | May 15 |
| 24°F | Apr 9 | Apr 22 | May 5 |
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 2 |
| 32°F | Sep 17 | Sep 30 | Oct 12 |
| 28°F | Sep 24 | Oct 8 | Oct 23 |
| 24°F | Oct 3 | Oct 17 | 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 | 105 days | 123 days | 139 days |
| 32°F | 121 days | 140 days | 158 days |
| 28°F | 140 days | 158 days | 177 days |
| 24°F | 159 days | 177 days | 196 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 |
|---|---|---|---|
| 58531 | 4a | -30 to -25°F | 16 km |
| 58565 | 4a | -30 to -25°F | 18 km |
| 58540 | 4a | -30 to -25°F | 23 km |
| 58759 | 4a | -30 to -25°F | 25 km |
| 58735 | 4a | -30 to -25°F | 26 km |
| 58576 | 4a | -30 to -25°F | 29 km |
| 58716 | 4a | -30 to -25°F | 31 km |
| 58779 | 4a | -30 to -25°F | 34 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 USC00323376, at 47.6539, -101.4197, elevation 589 m (1,932 ft).
- Data quality: Standard (24+ years of data), 28 years of freeze data.
- Average days per year at or below 32°F: 194.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Garrison (2 km)
- Riverdale (18 km)
- Max (21 km)
- Underwood (30 km)
- Turtle Lake (42 km)
- Washburn (49 km)
- Beulah 1 W (52 km)
- Velva (58 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.