Frost dates for San Gregorio 2 SE, CA
At San Gregorio 2 SE, the median last spring frost (32°F) is Mar 2 and the median first fall frost is Nov 25, for a typical growing season of 268 days. For a 90% chance that the last frost has passed, wait until Apr 15. Nearby ZIP codes are in USDA hardiness zone 9b.
- Mar 2Last spring frost (median)50% chance of 32°F after this date
- Apr 15Safer planting date10% chance of 32°F after this date
- Nov 25First fall frost (median)50% chance of 32°F by this date
- 268 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 | Mar 26 | Apr 26 | Jun 7 |
| 32°F | Dec 31 | Mar 2 | Apr 15 |
| 28°F | Dec 1 | Jan 2 | Feb 19 |
| 24°F | Dec 5 | Dec 19 | Jan 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 | Oct 2 | Nov 1 | Nov 24 |
| 32°F | Nov 1 | Nov 25 | Jan 1 |
| 28°F | Nov 21 | Dec 12 | Jan 26 |
| 24°F | Dec 2 | Dec 12 | Jan 5 |
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 | 144 days | 187 days | 222 days |
| 32°F | 218 days | 268 days | 326 days |
| 28°F | 309 days | 351 days | 365 days |
| 24°F | 357 days | 365 days | 365 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 99% |
| 28°F | 61% |
| 24°F | 11% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 94074 | 9b | 25 to 30°F | 3 km |
| 94060 | 9b | 25 to 30°F | 11 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 USC00047807, at 37.3117, -122.3617, elevation 84 m (275 ft).
- Data quality: Representative (10+ years), 14 years of freeze data.
- Average days per year at or below 32°F: 16.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Skyline Ridge Preserve (16 km)
- Woodside Fire Station 1 (16 km)
- Half Moon Bay (19 km)
- Redwood City (21 km)
- Palo Alto (24 km)
- Moffett Federal Airfield (30 km)
- Pacifica 4 SSE (33 km)
- San Francisco Intl Airport (34 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.