Frost dates · USDA zone 10a
Frost dates for Redwood City, CA
Redwood City, CA sees its last 32 °F night of spring around January 17 and its first of fall around December 12 — a 333-day freeze-free season in a typical year.
Pick a sauce; the Plan Builder runs this station's dates and hands back the calendar, plant count and gear list.
Freeze odds, by date
| Odds | Last spring freeze after | First fall freeze before |
|---|---|---|
| 9 years in 10 | Dec 20 (prior winter) | Jan 14 (next year) |
| Median — 1 year in 2 | Jan 17 | Dec 12 |
| 1 year in 10 | Feb 16 | Nov 24 |
The top row is the risky edge: in 9 years of 10 a spring freeze still comes after it, so tender transplants set out then need cover. The bottom row is the cautious date — only 1 year in 10 freezes after it — and the one to plan uncovered tender transplants against. Freeze-free season: 333 days median, at least 298 in 9 years of 10, no freeze at all in 1 year of 10. NOAA ranks season length year by year, so it is not the gap between two rows above. A hard freeze (28 °F) has a median last date of Dec 31 (prior winter) and first of Dec 26.
Redwood City planting calendar, 2027
Every row runs from the median last frost (Jan 17) and median first frost (Dec 12) above, using each cultivar's days to maturity. Same engine as the Plan Builder.
| Crop | Start indoors | Transplant / plant | First harvest | Days |
|---|---|---|---|---|
| Hardneck GarlicSiberian (porcelain hardneck) | — | Oct 15prior fall | Jun 12 | 240 from sow |
| Spanish OnionYellow Sweet Spanish (long-day) | Oct 25 | Dec 20 | Apr 9 | 110 from transplant |
| Mustard greensGarnet Giant (Brassica juncea) | Direct sow | Jan 17 | Feb 16 | 30 from sow |
| CilantroSlow Bolt (Coriandrum sativum) | Jan 3 | Jan 3 | Feb 17 | 45 from sow |
| Genovese BasilGenovese | Dec 20 | Jan 31 | Apr 1 | 60 from transplant |
| CayenneLong Slim Cayenne (Capsicum annuum) | Nov 22 | Jan 24 | Apr 9 | 75 from transplant |
| HabaneroOrange Habanero (Capsicum chinense) | Nov 8 | Jan 31 | May 6 | 95 from transplant |
| JalapeñoEarly Jalapeño (Capsicum annuum) | Nov 22 | Jan 24 | Apr 9 | 75 from transplant |
| Marconi Red PepperMarconi Red (Capsicum annuum) | Nov 22 | Jan 24 | Apr 14 | 80 from transplant |
| SerranoSerrano Tampiqueño (Capsicum annuum) | Nov 22 | Jan 24 | Apr 14 | 80 from transplant |
| Nantes CarrotScarlet Nantes | Jan 3 | Jan 3 | Mar 14 | 70 from sow |
| TomatilloToma Verde | Dec 6 | Jan 24 | Apr 4 | 70 from transplant |
| Roma TomatoRoma VF (determinate paste) | Dec 6 | Jan 24 | Apr 9 | 75 from transplant |
| San Marzano TomatoSan Marzano (indeterminate paste) | Dec 6 | Jan 24 | Apr 14 | 80 from transplant |
Tight means first harvest lands within two weeks of the median first fall frost: start that crop indoors on time or cover it in fall.
What sauce can Redwood City grow?
Each sauce, scheduled for a Redwood City container garden: when the first seeds go in and when enough fruit has ripened for one batch.
Redwood City frost questions
When is the last frost in Redwood City, CA?
The median last 32 °F freeze at REDWOOD CITY, CA is January 17: half of years see a later one. One year in ten, a freeze still comes after February 16; nine years in ten, it comes after December 20 (prior winter). Source: NOAA NCEI 1991–2020 U.S. Climate Normals.
When is the first frost in Redwood City, CA?
The median first 32 °F freeze of fall is December 12. One year in ten it arrives before November 24; nine years in ten, before January 14 (next year).
How long is the growing season in Redwood City, CA?
333 days between the last spring and first fall 32 °F freeze in a median year. Nine years in ten the season runs at least 298 days; one year in ten, no freeze at all.
What growing zone is Redwood City, CA?
USDA hardiness zone 10a, per the 2023 USDA Plant Hardiness Zone Map for ZIP 94063. A zone describes the coldest winter night, not when frost ends, so it is the wrong number for a planting calendar — the frost dates on this page are the right one.
When should I plant tomatoes in Redwood City, CA?
Start Roma VF (determinate paste) seeds indoors around Dec 6 and transplant around Jan 24, 1 week after the median last frost. To cut the freeze risk to one year in ten, wait for Feb 16. First ripe fruit lands around Apr 9.
When should I plant peppers in Redwood City, CA?
Sow jalapeño indoors on a heat mat around Nov 22; transplant no earlier than Jan 24, and wait past it until nights hold above 50 °F — that can run weeks later. First green pods around Apr 9.
Nearby in California
- San Mateolast frost Dec 29
- Palo Altolast frost Feb 1
- Haywardlast frost Jan 2
- Newarklast frost Jan 1
- Mountain Viewlast frost Jan 6
- Union Citylast frost Jan 2
All California frost dates → · How frost-date math drives a sowing calendar →