Frost dates for Moorhead 9 NE, MT
At Moorhead 9 NE, the median last spring frost (32°F) is May 17 and the median first fall frost is Sep 22, for a typical growing season of 126 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 22First fall frost (median)50% chance of 32°F by this date
- 126 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 15 | May 29 | Jun 15 |
| 32°F | May 5 | May 17 | May 31 |
| 28°F | Apr 23 | May 6 | May 21 |
| 24°F | Apr 9 | Apr 25 | 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 | Aug 29 | Sep 11 | Sep 26 |
| 32°F | Sep 7 | Sep 22 | Oct 5 |
| 28°F | Sep 17 | Oct 2 | Oct 16 |
| 24°F | Sep 28 | Oct 12 | Oct 27 |
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 | 84 days | 105 days | 123 days |
| 32°F | 106 days | 126 days | 147 days |
| 28°F | 126 days | 147 days | 167 days |
| 24°F | 149 days | 169 days | 190 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 |
|---|---|---|---|
| 59317 | 4b | -25 to -20°F | 26 km |
| 59314 | 4b | -25 to -20°F | 28 km |
| 82725 | 5a | -20 to -15°F | 33 km |
| 59062 | 5a | -20 to -15°F | 37 km |
| 59003 | 4b | -25 to -20°F | 50 km |
| 59316 | 4b | -25 to -20°F | 57 km |
| 82731 | 4b | -25 to -20°F | 59 km |
| 59343 | 4b | -25 to -20°F | 60 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 USC00245870, at 45.1758, -105.7517, elevation 982 m (3,220 ft).
- Data quality: Standard (24+ years of data), 28 years of freeze data.
- Average days per year at or below 32°F: 176.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Sonnette 7 SW (21 km)
- Biddle 8 SW (26 km)
- Broadus (40 km)
- Brandenberg (80 km)
- Powderville 8 NNE (94 km)
- Busby (103 km)
- Colstrip (105 km)
- Ridgeway 1 S (108 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.