Frost dates · USDA zone 10a
Frost dates for Highland, CA
Highland, CA sees its last 32 °F night of spring around January 27 and its first of fall around December 19 — a 329-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 21 (prior winter) | Jan 26 (next year) |
| Median — 1 year in 2 | Jan 27 | Dec 19 |
| 1 year in 10 | Feb 28 | Dec 1 |
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: 329 days median, at least 292 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 Jan 7 and first of Jan 1 (next year).
Highland planting calendar, 2027
Every row runs from the median last frost (Jan 27) and median first frost (Dec 19) 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) | Nov 4 | Dec 30 | Apr 19 | 110 from transplant |
| Mustard greensGarnet Giant (Brassica juncea) | Direct sow | Jan 27 | Feb 26 | 30 from sow |
| CilantroSlow Bolt (Coriandrum sativum) | Jan 13 | Jan 13 | Feb 27 | 45 from sow |
| Genovese BasilGenovese | Dec 30 | Feb 10 | Apr 11 | 60 from transplant |
| CayenneLong Slim Cayenne (Capsicum annuum) | Dec 2 | Feb 3 | Apr 19 | 75 from transplant |
| HabaneroOrange Habanero (Capsicum chinense) | Nov 18 | Feb 10 | May 16 | 95 from transplant |
| JalapeñoEarly Jalapeño (Capsicum annuum) | Dec 2 | Feb 3 | Apr 19 | 75 from transplant |
| Marconi Red PepperMarconi Red (Capsicum annuum) | Dec 2 | Feb 3 | Apr 24 | 80 from transplant |
| SerranoSerrano Tampiqueño (Capsicum annuum) | Dec 2 | Feb 3 | Apr 24 | 80 from transplant |
| Nantes CarrotScarlet Nantes | Jan 13 | Jan 13 | Mar 24 | 70 from sow |
| TomatilloToma Verde | Dec 16 | Feb 3 | Apr 14 | 70 from transplant |
| Roma TomatoRoma VF (determinate paste) | Dec 16 | Feb 3 | Apr 19 | 75 from transplant |
| San Marzano TomatoSan Marzano (indeterminate paste) | Dec 16 | Feb 3 | Apr 24 | 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 Highland grow?
Each sauce, scheduled for a Highland container garden: when the first seeds go in and when enough fruit has ripened for one batch.
Highland frost questions
When is the last frost in Highland, CA?
The median last 32 °F freeze at REDLANDS, CA is January 27: half of years see a later one. One year in ten, a freeze still comes after February 28; nine years in ten, it comes after December 21 (prior winter). Source: NOAA NCEI 1991–2020 U.S. Climate Normals.
When is the first frost in Highland, CA?
The median first 32 °F freeze of fall is December 19. One year in ten it arrives before December 1; nine years in ten, before January 26 (next year).
How long is the growing season in Highland, CA?
329 days between the last spring and first fall 32 °F freeze in a median year. Nine years in ten the season runs at least 292 days; one year in ten, no freeze at all.
What growing zone is Highland, CA?
USDA hardiness zone 10a, per the 2023 USDA Plant Hardiness Zone Map for ZIP 92346. 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 Highland, CA?
Start Roma VF (determinate paste) seeds indoors around Dec 16 and transplant around Feb 3, 1 week after the median last frost. To cut the freeze risk to one year in ten, wait for Feb 28. First ripe fruit lands around Apr 19.
When should I plant peppers in Highland, CA?
Sow jalapeño indoors on a heat mat around Dec 2; transplant no earlier than Feb 3, and wait past it until nights hold above 50 °F — that can run weeks later. First green pods around Apr 19.
Nearby in California
- Redlandslast frost Jan 27
- San Bernardinolast frost May 5
- Yucaipalast frost Jan 27
- Coltonlast frost Jan 10
- Rialtolast frost Jan 10
- Moreno Valleylast frost Jan 10
All California frost dates → · How frost-date math drives a sowing calendar →