Checking current alerts… View NWS forecast and alerts.
Will it freeze in Clearlake in the next 7 nights?
No overnight lows at or below 32°F are forecast in Clearlake during the next 7 nights in the available NWS frost forecast.
Tonight: forecast low 43°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 43°F Above 36°F · Mostly Clear
- Fri, Nov 6 45°F Above 36°F · Clear
- Sat, Nov 7 43°F Above 36°F · Mostly Clear
- Sun, Nov 8 43°F Above 36°F · Partly Cloudy
- Mon, Nov 9 42°F Above 36°F · Mostly Clear
- Tue, Nov 10 44°F Above 36°F · Partly Cloudy then Slight Chance Light Rain
- Wed, Nov 11 43°F Above 36°F · Chance Light Rain
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 Clearlake
The median first fall hard-freeze date (28°F) is November 21, from NOAA’s 1991–2020 Climate Normals at Clearlake 4 SE. This is the 50% probability date, not a forecast for this year.
| 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 | Apr 14 · Apr 30 · May 16 | Oct 11 · Oct 27 · Nov 7 | 178 days |
| 32°F freeze | Mar 24 · Apr 10 · Apr 30 | Oct 24 · Nov 6 · Nov 20 | 209 days |
| 28°F hard freeze | Feb 12 · Mar 14 · Apr 7 | Nov 4 · Nov 21 · Dec 8 | 250 days |
Average high temperature by month
1991–2020 normals at Clearlake 4 SE
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 Clearlake, CA come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Clearlake 4 SE (station USC00041806, elevation 1,349 ft), 4.3 mi from Clearlake. 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 Clearlake
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| Lakeport, CA | 16 mi | Mar 5 | Nov 21 |
| Cloverdale, CA | 24 mi | Feb 25 | Dec 3 |
| Healdsburg, CA | 27 mi | Feb 15 | Dec 2 |
| Williams, CA | 30 mi | Feb 14 | Dec 1 |
| Windsor, CA | 30 mi | Mar 2 | Nov 20 |
| St. Helena, CA | 32 mi | Feb 3 | Dec 4 |
| Ukiah, CA | 34 mi | Mar 19 | Nov 20 |
| Santa Rosa, CA | 36 mi | Feb 25 | Dec 1 |
| Colusa, CA | 37 mi | Feb 14 | Dec 1 |
| Sebastopol, CA | 40 mi | Mar 20 | Nov 13 |
Frequently asked questions
When is the last frost in Clearlake?
On average, the last spring frost (32°F) in Clearlake is around April 10. In about 1 year in 10 it comes after April 30, and in 9 years in 10 it comes after March 24.
When is the first frost in Clearlake?
The first fall frost (32°F) usually arrives around November 6. There’s a 10% chance of a freeze by October 24 and a 90% chance by November 20.
Can it frost in Clearlake 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 April 30.
What growing zone is Clearlake?
Clearlake is in USDA Plant Hardiness Zone 9a (average annual extreme minimum temperature 20 to 25°F), based on the 2023 USDA map for ZIP code 95422. See growing zones in California.
More: all California frost dates · California growing zones · frost vs. freeze