Frost dates · USDA zone 9b
Frost dates for Concord, CA
Concord, CA sees its last 32 °F night of spring around January 9 and its first of fall around December 14 — a 343-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 16 (prior winter) | Jan 16 (next year) |
| Median — 1 year in 2 | Jan 9 | Dec 14 |
| 1 year in 10 | Feb 12 | Nov 28 |
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: 343 days median, at least 313 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 30 (prior winter) and first of Dec 23.
Concord planting calendar, 2027
Every row runs from the median last frost (Jan 9) and median first frost (Dec 14) 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 17 | Dec 12 | Apr 1 | 110 from transplant |
| Mustard greensGarnet Giant (Brassica juncea) | Direct sow | Jan 9 | Feb 8 | 30 from sow |
| CilantroSlow Bolt (Coriandrum sativum) | Dec 26 | Dec 26 | Feb 9 | 45 from sow |
| Genovese BasilGenovese | Dec 12 | Jan 23 | Mar 24 | 60 from transplant |
| CayenneLong Slim Cayenne (Capsicum annuum) | Nov 14 | Jan 16 | Apr 1 | 75 from transplant |
| HabaneroOrange Habanero (Capsicum chinense) | Oct 31 | Jan 23 | Apr 28 | 95 from transplant |
| JalapeñoEarly Jalapeño (Capsicum annuum) | Nov 14 | Jan 16 | Apr 1 | 75 from transplant |
| Marconi Red PepperMarconi Red (Capsicum annuum) | Nov 14 | Jan 16 | Apr 6 | 80 from transplant |
| SerranoSerrano Tampiqueño (Capsicum annuum) | Nov 14 | Jan 16 | Apr 6 | 80 from transplant |
| Nantes CarrotScarlet Nantes | Dec 26 | Dec 26 | Mar 6 | 70 from sow |
| TomatilloToma Verde | Nov 28 | Jan 16 | Mar 27 | 70 from transplant |
| Roma TomatoRoma VF (determinate paste) | Nov 28 | Jan 16 | Apr 1 | 75 from transplant |
| San Marzano TomatoSan Marzano (indeterminate paste) | Nov 28 | Jan 16 | Apr 6 | 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 Concord grow?
Each sauce, scheduled for a Concord container garden: when the first seeds go in and when enough fruit has ripened for one batch.
Concord frost questions
When is the last frost in Concord, CA?
The median last 32 °F freeze at CONCORD BUCHANAN FLD, CA is January 9: half of years see a later one. One year in ten, a freeze still comes after February 12; nine years in ten, it comes after December 16 (prior winter). Source: NOAA NCEI 1991–2020 U.S. Climate Normals.
When is the first frost in Concord, CA?
The median first 32 °F freeze of fall is December 14. One year in ten it arrives before November 28; nine years in ten, before January 16 (next year).
How long is the growing season in Concord, CA?
343 days between the last spring and first fall 32 °F freeze in a median year. Nine years in ten the season runs at least 313 days; one year in ten, no freeze at all.
What growing zone is Concord, CA?
USDA hardiness zone 9b, per the 2023 USDA Plant Hardiness Zone Map for ZIP 94519. 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 Concord, CA?
Start Roma VF (determinate paste) seeds indoors around Nov 28 and transplant around Jan 16, 1 week after the median last frost. To cut the freeze risk to one year in ten, wait for Feb 12. First ripe fruit lands around Apr 1.
When should I plant peppers in Concord, CA?
Sow jalapeño indoors on a heat mat around Nov 14; transplant no earlier than Jan 16, and wait past it until nights hold above 50 °F — that can run weeks later. First green pods around Apr 1.
Nearby in California
- Walnut Creeklast frost Mar 8
- Pittsburglast frost Jan 9
- Danvillelast frost Mar 8
- Antiochlast frost Jan 12
- San Ramonlast frost Feb 15
- Brentwoodlast frost Jan 12
All California frost dates → · How frost-date math drives a sowing calendar →