Frost dates for Mount Shasta, CA
At Mount Shasta, the median last spring frost (32°F) is May 15 and the median first fall frost is Oct 6, for a typical growing season of 143 days. For a 90% chance that the last frost has passed, wait until Jun 5. Nearby ZIP codes are in USDA hardiness zone 8a.
- May 15Last spring frost (median)50% chance of 32°F after this date
- Jun 5Safer planting date10% chance of 32°F after this date
- Oct 6First fall frost (median)50% chance of 32°F by this date
- 143 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 19 | Jun 6 | Jun 27 |
| 32°F | Apr 29 | May 15 | Jun 5 |
| 28°F | Apr 11 | Apr 29 | May 14 |
| 24°F | Mar 16 | Apr 9 | Apr 30 |
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 3 | Sep 19 | Oct 5 |
| 32°F | Sep 20 | Oct 6 | Oct 24 |
| 28°F | Oct 6 | Oct 25 | Nov 9 |
| 24°F | Oct 24 | Nov 7 | Nov 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 | 74 days | 101 days | 127 days |
| 32°F | 115 days | 143 days | 167 days |
| 28°F | 154 days | 179 days | 204 days |
| 24°F | 184 days | 210 days | 240 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 |
|---|---|---|---|
| 96067 | 8a | 10 to 15°F | 1 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 USC00045983, at 41.3219, -122.3178, elevation 1101 m (3,613 ft).
- Data quality: Representative (10+ years), 25 years of freeze data.
- Average days per year at or below 32°F: 134.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Mount Shasta (2 km)
- Dunsmuir Trtmt Pl (16 km)
- McCloud (17 km)
- Callahan (42 km)
- Yreka (50 km)
- Montague Siskiyou Co Airport (53 km)
- Shasta Dam (68 km)
- Cecilville (72 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.