Frost dates for Keene 3s, ND
At Keene 3s, the median last spring frost (32°F) is May 20 and the median first fall frost is Sep 20, for a typical growing season of 121 days. For a 90% chance that the last frost has passed, wait until Jun 2. Nearby ZIP codes are in USDA hardiness zone 4a.
- May 20Last spring frost (median)50% chance of 32°F after this date
- Jun 2Safer planting date10% chance of 32°F after this date
- Sep 20First fall frost (median)50% chance of 32°F by this date
- 121 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 17 | May 30 | Jun 20 |
| 32°F | May 8 | May 20 | Jun 2 |
| 28°F | Apr 27 | May 10 | May 24 |
| 24°F | Apr 15 | Apr 30 | May 13 |
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 27 | Sep 11 | Sep 23 |
| 32°F | Sep 5 | Sep 20 | Oct 2 |
| 28°F | Sep 13 | Sep 28 | Oct 14 |
| 24°F | Sep 22 | Oct 9 | Oct 24 |
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 | 75 days | 102 days | 121 days |
| 32°F | 101 days | 121 days | 140 days |
| 28°F | 121 days | 141 days | 160 days |
| 24°F | 139 days | 160 days | 180 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 |
|---|---|---|---|
| 58847 | 4a | -30 to -25°F | 1 km |
| 58763 | 4a | -30 to -25°F | 27 km |
| 58757 | 4a | -30 to -25°F | 36 km |
| 58770 | 4a | -30 to -25°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 USC00324571, at 47.8967, -102.9208, elevation 753 m (2,470 ft).
- Data quality: Standard (24+ years of data), 30 years of freeze data.
- Average days per year at or below 32°F: 184.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Watford City (29 km)
- Watford City 14s (42 km)
- Tioga 1e (56 km)
- Grassy Butte 2ene (59 km)
- Killdeer (60 km)
- Williston Sloulin Intl Airport (62 km)
- Stanley 3 NNW (64 km)
- Dunn Center 1e (66 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.