Frost dates for Gildford, MT
At Gildford, the median last spring frost (32°F) is May 24 and the median first fall frost is Sep 15, for a typical growing season of 114 days. For a 90% chance that the last frost has passed, wait until Jun 7. Nearby ZIP codes are in USDA hardiness zones 3b to 4a.
- May 24Last spring frost (median)50% chance of 32°F after this date
- Jun 7Safer planting date10% chance of 32°F after this date
- Sep 15First fall frost (median)50% chance of 32°F by this date
- 114 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 25 | Jun 7 | Jun 26 |
| 32°F | May 12 | May 24 | Jun 7 |
| 28°F | Apr 29 | May 12 | May 27 |
| 24°F | Apr 16 | Apr 30 | May 11 |
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 15 | Sep 2 | Sep 15 |
| 32°F | Aug 29 | Sep 15 | Sep 28 |
| 28°F | Sep 12 | Sep 26 | Oct 6 |
| 24°F | Sep 20 | Oct 3 | Oct 17 |
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 | 60 days | 85 days | 105 days |
| 32°F | 92 days | 114 days | 131 days |
| 28°F | 117 days | 136 days | 153 days |
| 24°F | 136 days | 155 days | 175 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 |
|---|---|---|---|
| 59525 | 3b | -35 to -30°F | 9 km |
| 59528 | 4a | -30 to -25°F | 11 km |
| 59532 | 4a | -30 to -25°F | 17 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 USC00243530, at 48.5647, -110.3028, elevation 860 m (2,820 ft).
- Data quality: Standard (24+ years of data), 30 years of freeze data.
- Average days per year at or below 32°F: 190.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Joplin (35 km)
- Fort Assiniboine (38 km)
- Rudyard 21 N (39 km)
- Rudyard 19s (39 km)
- Havre City Co Airport (40 km)
- Simpson 6 N - Wildhorse (49 km)
- Chester (49 km)
- Big Sandy (51 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.