Frost dates for Skyline Ridge Preserve, CA
At Skyline Ridge Preserve, the median last spring frost (32°F) is Mar 21 and the median first fall frost is Dec 15, for a typical growing season of 275 days. For a 90% chance that the last frost has passed, wait until Apr 28. Nearby ZIP codes are in USDA hardiness zone 9b.
- Mar 21Last spring frost (median)50% chance of 32°F after this date
- Apr 28Safer planting date10% chance of 32°F after this date
- Dec 15First fall frost (median)50% chance of 32°F by this date
- 275 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 25 | Apr 26 | May 27 |
| 32°F | Jan 19 | Mar 21 | Apr 28 |
| 28°F | Dec 15 | Jan 29 | Mar 30 |
| 24°F | Dec 9 | Jan 1 | Mar 6 |
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 | Nov 4 | Nov 25 | Dec 15 |
| 32°F | Nov 21 | Dec 15 | Jan 30 |
| 28°F | Dec 3 | Jan 4 | Mar 9 |
| 24°F | Dec 6 | Dec 30 | Mar 6 |
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 | 175 days | 212 days | 252 days |
| 32°F | 227 days | 275 days | 337 days |
| 28°F | 289 days | 361 days | 365 days |
| 24°F | 364 days | 365 days | 365 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 98% |
| 28°F | 56% |
| 24°F | 11% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 94022 | 9b | 25 to 30°F | 6 km |
| 94020 | 9b | 25 to 30°F | 6 km |
| 94021 | 9b | 25 to 30°F | 9 km |
| 95014 | 9b | 25 to 30°F | 9 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 USC00048273, at 37.3133, -122.1850, elevation 692 m (2,270 ft).
- Data quality: Representative (10+ years), 17 years of freeze data.
- Average days per year at or below 32°F: 11.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Woodside Fire Station 1 (14 km)
- Palo Alto (15 km)
- San Gregorio 2 SE (16 km)
- Moffett Federal Airfield (16 km)
- Redwood City (19 km)
- Los Gatos (22 km)
- San Jose (24 km)
- San Jose (25 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.