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Will it freeze in San Anselmo in the next 7 nights?
No overnight lows at or below 32°F are forecast in San Anselmo during the next 7 nights in the available NWS frost forecast.
Tonight: forecast low 50°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 50°F Above 36°F · Mostly Clear
- Fri, Nov 6 50°F Above 36°F · Mostly Clear
- Sat, Nov 7 51°F Above 36°F · Mostly Clear
- Sun, Nov 8 51°F Above 36°F · Partly Cloudy
- Mon, Nov 9 51°F Above 36°F · Mostly Clear
- Tue, Nov 10 52°F Above 36°F · Partly Cloudy then Slight Chance Light Rain
- Wed, Nov 11 52°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 San Anselmo
Most years have no 28°F hard freeze at San Rafael Civic Center, 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 6 · Feb 22 · Apr 6 | Nov 15 · Dec 5 · Jan 1 | 287 days |
| 32°F freeze | Dec 14 · Jan 11 · Feb 25 | Dec 2 · Dec 21 · Feb 9 | 349 days |
| 28°F hard freeze | Dec 11 · Dec 31 · Feb 21 | Dec 7 · Dec 29 · Feb 18 | 365 days |
Average high temperature by month
1991–2020 normals at San Rafael Civic Center
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 San Anselmo, CA come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: San Rafael Civic Center (station USC00047880, elevation 120 ft), 2.1 mi from San Anselmo. 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 San Anselmo
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| Fairfax, CA | 1.2 mi | Jan 11 | Dec 21 |
| San Rafael, CA | 3.7 mi | Jan 11 | Dec 21 |
| Larkspur, CA | 3.7 mi | Jan 16 | Dec 18 |
| Corte Madera, CA | 5.0 mi | Jan 16 | Dec 18 |
| Mill Valley, CA | 5.6 mi | Jan 16 | Dec 18 |
| Novato, CA | 7.5 mi | Jan 11 | Dec 21 |
| Tiburon, CA | 8.7 mi | rare | rare |
| Sausalito, CA | 9.3 mi | Jan 16 | Dec 18 |
| Richmond, CA | 12 mi | rare | rare |
| San Pablo, CA | 12 mi | rare | rare |
Frequently asked questions
When is the last frost in San Anselmo?
On average, the last spring frost (32°F) in San Anselmo is around January 11. In about 1 year in 10 it comes after February 25, and in 9 years in 10 it comes after December 14.
When is the first frost in San Anselmo?
The first fall frost (32°F) usually arrives around December 21. There’s a 10% chance of a freeze by December 2 and a 90% chance by February 9.
Can it frost in San Anselmo 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 22.
What growing zone is San Anselmo?
San Anselmo is in USDA Plant Hardiness Zone 9b (average annual extreme minimum temperature 25 to 30°F), based on the 2023 USDA map for ZIP code 94960. See growing zones in California.
More: all California frost dates · California growing zones · frost vs. freeze