Frost dates / California / Irvine
Frost dates in Irvine, CA
The station on this page is TUSTIN IRVINE RCH, CA US (USC00049087), 1.9 miles from the city point. Population in the Census 2024 estimate is 318,683.
Zone 10aUSDA average annual extreme minimum 30°F to 35°F, from ZIP 92604 (1.3 miles from the city point used on this page).
Outside the median season Growing seasonTicks: 10%, 50%, and 90%
Last 32°F in spring
NCEI’s probability is the chance the last spring minimum of 32°F or lower occurs on or after the date.
| Probability | Date | How to read it |
|---|---|---|
| 90% | December 14 | Earlier date. A last 32°F on or after this day is common. |
| 50% | January 5 | Median. |
| 10% | February 2 | Later date. A last 32°F on or after this day is uncommon. |
First 32°F in fall
NCEI’s probability is the chance the first autumn minimum of 32°F or lower occurs on or before the date.
| Probability | Date | How to read it |
|---|---|---|
| 10% | December 3 | Earlier date. A first 32°F on or before this day is uncommon. |
| 50% | December 25 | Median. |
| 90% | January 20 | Later date. A first 32°F on or before this day is common. |
32°F growing-season length
Days between the last spring 32°F and the first autumn 32°F. The figure is a length the season meets or exceeds at that probability, from NCEI, not a subtraction done on this site.
| Probability the season is at least this long | Days |
|---|---|
| 10% | 365 |
| 50% | 365 |
| 90% | 331 |
36°F threshold
| 10% | 50% | 90% | |
|---|---|---|---|
| Last, on or after | March 5 | February 1 | January 3 |
| First, on or before | November 24 | December 13 | January 8 |
| Season at least | 345 days | 311 days | 275 days |
Station TUSTIN IRVINE RCH, CA US (USC00049087). Completeness flag R, 13 years used for the 32°F dates. NCEI’s annual probability of at least one day at or below 32°F is 50.4%. Freeze dates are conditional on that threshold occurring. Elevation 71.6 m. The same probability language applies to the 28°F and 36°F rows when those dates passed the same quality checks.
Planting calendar for Irvine · Zone 10a
Check a crop against this station
Irvine, CA
Zone 10aAverage annual extreme minimum 30°F to 35°F
Outside the median season Growing seasonTicks: 10%, 50%, and 90%
California. Nearest qualified station: TUSTIN IRVINE RCH, CA US (USC00049087), 1.9 miles. Median last 32°F January 5. Median first 32°F December 25. The 50% growing-season length is 365 days.
Open the ZIP page · Crop guides for California
32°F probabilities at this station
| 10% | 50% | 90% | |
|---|---|---|---|
| Last 32°F on or after | February 2 | January 5 | December 14 |
| First 32°F on or before | December 3 | December 25 | January 20 |
Column order matches the NCEI file: for the last freeze, 10% is the later date and 90% is the earlier date. How to read the probabilities.
Planting calendar
Windows below are from UC ANR, UC Master Gardener Program, Time of planting, retrieved 2026-10-10. North and North Coast = Monterey County north; South Coast = San Luis Obispo County south; Interior Valleys = Sacramento, San Joaquin, and similar valleys; Desert Valleys = Imperial and Coachella Valleys. Source line on the page: California Master Gardener Handbook, Table 13.2, Adapted from Vegetable Gardening Illustrated 1994.
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