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Will it freeze in Santa Rosa in the next 7 nights?
No overnight lows at or below 32°F are forecast in Santa Rosa during the next 7 nights in the available NWS frost forecast.
Tonight: forecast low 45°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 45°F Above 36°F · Mostly Clear
- Fri, Nov 6 44°F Above 36°F · Mostly Clear
- Sat, Nov 7 45°F Above 36°F · Partly Cloudy then Areas Of Fog
- Sun, Nov 8 46°F Above 36°F · Mostly Cloudy then Areas Of Fog
- Mon, Nov 9 46°F Above 36°F · Partly Cloudy then Patchy Fog
- Tue, Nov 10 48°F Above 36°F · Partly Cloudy then Areas Of Fog
- Wed, Nov 11 47°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 Santa Rosa
The median first fall hard-freeze date (28°F) is December 16, from NOAA’s 1991–2020 Climate Normals at Santa Rosa. 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 | Mar 6 · Apr 3 · Apr 25 | Oct 31 · Nov 14 · Dec 1 | 223 days |
| 32°F freeze | Jan 21 · Feb 25 · Mar 29 | Nov 10 · Dec 1 · Dec 24 | 279 days |
| 28°F hard freeze | Dec 22 · Jan 20 · Feb 24 | Nov 26 · Dec 16 · Jan 19 | 335 days |
Average high temperature by month
1991–2020 normals at Santa Rosa
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 Santa Rosa, CA come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Santa Rosa (station USC00047965, elevation 166 ft), 0.8 mi from Santa Rosa. 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 Santa Rosa
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| Rohnert Park, CA | 6.8 mi | Feb 25 | Dec 1 |
| Sebastopol, CA | 7.5 mi | Mar 20 | Nov 13 |
| Cotati, CA | 8.1 mi | Feb 28 | Nov 25 |
| Windsor, CA | 8.7 mi | Mar 2 | Nov 20 |
| St. Helena, CA | 14 mi | Feb 3 | Dec 4 |
| Petaluma, CA | 15 mi | Feb 28 | Nov 25 |
| Healdsburg, CA | 15 mi | Feb 15 | Dec 2 |
| Sonoma, CA | 17 mi | Mar 2 | Nov 27 |
| Napa, CA | 24 mi | Feb 12 | Dec 4 |
| Novato, CA | 26 mi | Jan 11 | Dec 21 |
Frequently asked questions
When is the last frost in Santa Rosa?
On average, the last spring frost (32°F) in Santa Rosa is around February 25. In about 1 year in 10 it comes after March 29, and in 9 years in 10 it comes after January 21.
When is the first frost in Santa Rosa?
The first fall frost (32°F) usually arrives around December 1. There’s a 10% chance of a freeze by November 10 and a 90% chance by December 24.
Can it frost in Santa Rosa 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 3.
What growing zone is Santa Rosa?
Santa Rosa 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 95405. See growing zones in California.
More: all California frost dates · California growing zones · UV index today in Santa Rosa · frost vs. freeze