Frost dates for Petersburg 2 N, ND
At Petersburg 2 N, the median last spring frost (32°F) is May 11 and the median first fall frost is Sep 28, for a typical growing season of 138 days. For a 90% chance that the last frost has passed, wait until May 25. Nearby ZIP codes are in USDA hardiness zone 4a.
- May 11Last spring frost (median)50% chance of 32°F after this date
- May 25Safer planting date10% chance of 32°F after this date
- Sep 28First fall frost (median)50% chance of 32°F by this date
- 138 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 2 |
| 32°F | Apr 29 | May 11 | May 25 |
| 28°F | Apr 19 | May 2 | May 16 |
| 24°F | Apr 10 | Apr 24 | 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 7 | Sep 20 | Oct 1 |
| 32°F | Sep 16 | Sep 28 | Oct 10 |
| 28°F | Sep 25 | Oct 7 | Oct 21 |
| 24°F | Oct 1 | Oct 17 | Oct 30 |
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 | 101 days | 120 days | 137 days |
| 32°F | 119 days | 138 days | 155 days |
| 28°F | 137 days | 156 days | 176 days |
| 24°F | 155 days | 176 days | 194 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 |
|---|---|---|---|
| 58272 | 4a | -30 to -25°F | 4 km |
| 58259 | 4a | -30 to -25°F | 8 km |
| 58266 | 4a | -30 to -25°F | 12 km |
| 58224 | 4a | -30 to -25°F | 16 km |
| 58231 | 4a | -30 to -25°F | 23 km |
| 58344 | 4a | -30 to -25°F | 25 km |
| 58250 | 4a | -30 to -25°F | 27 km |
| 58321 | 4a | -30 to -25°F | 29 km |
| 58254 | 4a | -30 to -25°F | 31 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 USC00327027, at 48.0356, -98.0097, elevation 467 m (1,532 ft).
- Data quality: Standard (24+ years of data), 29 years of freeze data.
- Average days per year at or below 32°F: 192.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Larimore 4sw (29 km)
- Edmore 4nw (60 km)
- Grafton (61 km)
- Grand Forks Intl Airport (62 km)
- Devils Lake Kdlr (64 km)
- Devils Lake (67 km)
- Grand Forks Univ (nws) (69 km)
- Mc Henry 3w (69 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.