Frost dates · USDA zone 10a
Frost dates for San Rafael, CA
San Rafael, CA sees its last 32 °F night of spring around January 11 and its first of fall around December 21 — a 349-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 14 (prior winter) | Feb 9 (next year) |
| Median — 1 year in 2 | Jan 11 | Dec 21 |
| 1 year in 10 | Feb 25 | Dec 2 |
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: 349 days median, at least 304 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 29.
San Rafael planting calendar, 2027
Every row runs from the median last frost (Jan 11) and median first frost (Dec 21) 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 19 | Dec 14 | Apr 3 | 110 from transplant |
| Mustard greensGarnet Giant (Brassica juncea) | Direct sow | Jan 11 | Feb 10 | 30 from sow |
| CilantroSlow Bolt (Coriandrum sativum) | Dec 28 | Dec 28 | Feb 11 | 45 from sow |
| Genovese BasilGenovese | Dec 14 | Jan 25 | Mar 26 | 60 from transplant |
| CayenneLong Slim Cayenne (Capsicum annuum) | Nov 16 | Jan 18 | Apr 3 | 75 from transplant |
| HabaneroOrange Habanero (Capsicum chinense) | Nov 2 | Jan 25 | Apr 30 | 95 from transplant |
| JalapeñoEarly Jalapeño (Capsicum annuum) | Nov 16 | Jan 18 | Apr 3 | 75 from transplant |
| Marconi Red PepperMarconi Red (Capsicum annuum) | Nov 16 | Jan 18 | Apr 8 | 80 from transplant |
| SerranoSerrano Tampiqueño (Capsicum annuum) | Nov 16 | Jan 18 | Apr 8 | 80 from transplant |
| Nantes CarrotScarlet Nantes | Dec 28 | Dec 28 | Mar 8 | 70 from sow |
| TomatilloToma Verde | Nov 30 | Jan 18 | Mar 29 | 70 from transplant |
| Roma TomatoRoma VF (determinate paste) | Nov 30 | Jan 18 | Apr 3 | 75 from transplant |
| San Marzano TomatoSan Marzano (indeterminate paste) | Nov 30 | Jan 18 | Apr 8 | 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 San Rafael grow?
Each sauce, scheduled for a San Rafael container garden: when the first seeds go in and when enough fruit has ripened for one batch.
San Rafael frost questions
When is the last frost in San Rafael, CA?
The median last 32 °F freeze at SAN RAFAEL CIVIC CTR, CA is January 11: half of years see a later one. One year in ten, a freeze still comes after February 25; nine years in ten, it comes after December 14 (prior winter). Source: NOAA NCEI 1991–2020 U.S. Climate Normals.
When is the first frost in San Rafael, CA?
The median first 32 °F freeze of fall is December 21. One year in ten it arrives before December 2; nine years in ten, before February 9 (next year).
How long is the growing season in San Rafael, CA?
349 days between the last spring and first fall 32 °F freeze in a median year. Nine years in ten the season runs at least 304 days; one year in ten, no freeze at all.
What growing zone is San Rafael, CA?
USDA hardiness zone 10a, per the 2023 USDA Plant Hardiness Zone Map for ZIP 94901. 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 San Rafael, CA?
Start Roma VF (determinate paste) seeds indoors around Nov 30 and transplant around Jan 18, 1 week after the median last frost. To cut the freeze risk to one year in ten, wait for Feb 25. First ripe fruit lands around Apr 3.
When should I plant peppers in San Rafael, CA?
Sow jalapeño indoors on a heat mat around Nov 16; transplant no earlier than Jan 18, and wait past it until nights hold above 50 °F — that can run weeks later. First green pods around Apr 3.
Nearby in California
- Novatolast frost Jan 11
- Richmondlast frost Jan 4
- Berkeleylast frost Jan 3
- Vallejolast frost Mar 5
- Petalumalast frost Feb 28
- Daly Citylast frost Dec 30
All California frost dates → · How frost-date math drives a sowing calendar →