Frost dates for Middle Fork Lodge, ID
At Middle Fork Lodge, the median last spring frost (32°F) is May 21 and the median first fall frost is Sep 18, for a typical growing season of 115 days. For a 90% chance that the last frost has passed, wait until Jun 13. Nearby ZIP codes are in USDA hardiness zones 5a to 6a.
- May 21Last spring frost (median)50% chance of 32°F after this date
- Jun 13Safer planting date10% chance of 32°F after this date
- Sep 18First fall frost (median)50% chance of 32°F by this date
- 115 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 29 | Jun 16 | Jul 7 |
| 32°F | May 7 | May 21 | Jun 13 |
| 28°F | Apr 19 | May 4 | May 18 |
| 24°F | Mar 30 | Apr 15 | May 2 |
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 21 | Sep 4 | Sep 19 |
| 32°F | Sep 3 | Sep 18 | Oct 5 |
| 28°F | Sep 17 | Oct 2 | Oct 20 |
| 24°F | Sep 29 | Oct 17 | Nov 2 |
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 | 54 days | 78 days | 101 days |
| 32°F | 90 days | 115 days | 139 days |
| 28°F | 127 days | 151 days | 174 days |
| 24°F | 158 days | 181 days | 208 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 |
|---|---|---|---|
| 83677 | 5a | -20 to -15°F | 40 km |
| 83278 | 5b | -15 to -10°F | 45 km |
| 83469 | 5b | -15 to -10°F | 62 km |
| 83637 | 6a | -10 to -5°F | 69 km |
| 83611 | 5a | -20 to -15°F | 70 km |
| 83638 | 5a | -20 to -15°F | 71 km |
| 83227 | 5b | -15 to -10°F | 75 km |
| 83235 | 5b | -15 to -10°F | 77 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 USC00105897, at 44.7189, -115.0150, elevation 1366 m (4,480 ft).
- Data quality: Representative (10+ years), 21 years of freeze data.
- Average days per year at or below 32°F: 203.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Taylor Rch (44 km)
- Yellowpine (47 km)
- Deadwood Lodge (53 km)
- Stanley (56 km)
- Stanley Ranger Station (61 km)
- Challis Airport (67 km)
- Warren (80 km)
- Cascade 1 NW (85 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.