Checking current alerts… View NWS forecast and alerts.
Will it freeze in Costa Mesa in the next 7 nights?
No overnight lows at or below 32°F are forecast in Costa Mesa during the next 7 nights in the available NWS frost forecast.
Tonight: forecast low 58°F. Above 36°F.
NWS forecast period: Thu, Nov 5, 6:00 PM PST to Fri, Nov 6, 6:00 AM PST.
No nights at or below 36°F in the National Weather Service forecast for the next 7 nights.
- Tonight 58°F Above 36°F · Mostly Clear
- Fri, Nov 6 63°F Above 36°F · Clear
- Sat, Nov 7 64°F Above 36°F · Clear
- Sun, Nov 8 64°F Above 36°F · Mostly Clear
- Mon, Nov 9 63°F Above 36°F · Mostly Clear
- Tue, Nov 10 61°F Above 36°F · Mostly Clear
- Wed, Nov 11 59°F Above 36°F · Mostly Clear then Slight Chance Rain Showers
Overnight lows from the National Weather Service forecast for this location. This covers the available forecast window, not the first freeze of the whole season. Frost can form above 32°F on clear, calm nights.
Frost and freeze probabilities
Freeze dates shift from year to year. Spring percentages describe the chance of a freeze after the stated date; fall percentages describe the chance of a freeze by that date. The 10% spring date is the cautious one: a later freeze happens about 1 year in 10.
These dates describe historical probabilities, not this year’s forecast or the earliest and latest possible freezes. Different weather stations or probability thresholds can produce different published dates for the same city.
Average first hard freeze in Costa Mesa
Most years have no 28°F hard freeze at Tustin Irvine Ranch, according to NOAA’s 1991–2020 Climate Normals. Check the short-term forecast above during cold snaps.
| Temperature | Last spring date 90% · 50% · 10% chance of a later freeze | First fall date 10% · 50% · 90% chance of an earlier freeze | Season |
|---|---|---|---|
| 36°F frost possible | Jan 3 · Feb 1 · Mar 5 | Nov 24 · Dec 13 · Jan 8 | 311 days |
| 32°F freeze | Dec 14 · Jan 5 · Feb 2 | Dec 3 · Dec 25 · Jan 20 | 365 days |
| 28°F hard freeze | rare in most years | rare in most years | 365 days |
Average high temperature by month
1991–2020 normals at Tustin Irvine Ranch
Average low temperature by month
Months with lows near or below freezing carry frost risk
Where these frost dates come from
The frost dates for Costa Mesa, CA come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Tustin Irvine Ranch (station USC00049087, elevation 235 ft), 9.4 mi from Costa Mesa. Local conditions (valleys, hilltops, distance to water, city heat) can shift frost dates by days or weeks. The hardiness zone is from the 2023 USDA Plant Hardiness Zone Map (USDA ARS and Oregon State University PRISM). See our methodology.
Frost dates near Costa Mesa
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| Fountain Valley, CA | 3.7 mi | rare | rare |
| Newport Beach, CA | 3.7 mi | rare | rare |
| Santa Ana, CA | 5.0 mi | rare | rare |
| Huntington Beach, CA | 5.6 mi | rare | rare |
| Tustin, CA | 7.5 mi | rare | rare |
| Westminster, CA | 7.5 mi | rare | rare |
| Irvine, CA | 8.1 mi | rare | rare |
| Garden Grove, CA | 8.1 mi | rare | rare |
| Orange, CA | 8.7 mi | rare | rare |
| Stanton, CA | 11 mi | rare | rare |
Frequently asked questions
When is the last frost in Costa Mesa?
Costa Mesa doesn’t reach 32°F in a typical year, according to NOAA’s 1991–2020 normals for the nearest station.
When is the first frost in Costa Mesa?
Freezes are uncommon here; check the 7-night forecast above during cold snaps.
Can it frost in Costa Mesa after the last frost date?
Yes. Frost can form on clear, calm nights even when the air stays above 32°F. Temperatures of 36°F or lower, cold enough for frost on exposed plants, have a 50% chance of occurring after February 1.
What growing zone is Costa Mesa?
Costa Mesa is in USDA Plant Hardiness Zone 10b (average annual extreme minimum temperature 35 to 40°F), based on the 2023 USDA map for ZIP code 92626. See growing zones in California.
More: all California frost dates · California growing zones · UV index today in Costa Mesa · frost vs. freeze