Checking current alerts… View NWS forecast and alerts.
Will it freeze in Rohnert Park in the next 7 nights?
No overnight lows at or below 32°F are forecast in Rohnert Park 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 · Areas Of Fog
- Fri, Nov 6 42°F Above 36°F · Mostly Clear then Patchy Fog
- Sat, Nov 7 45°F Above 36°F · Areas Of Fog
- Sun, Nov 8 45°F Above 36°F · Areas Of Fog
- Mon, Nov 9 45°F Above 36°F · Areas Of Fog
- Tue, Nov 10 46°F Above 36°F · Areas Of Fog
- Wed, Nov 11 46°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 Rohnert Park
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 Rohnert Park, CA come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Santa Rosa (station USC00047965, elevation 166 ft), 7.5 mi from Rohnert Park. 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 Rohnert Park
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| Cotati, CA | 1.2 mi | Feb 28 | Nov 25 |
| Santa Rosa, CA | 6.8 mi | Feb 25 | Dec 1 |
| Sebastopol, CA | 7.5 mi | Mar 20 | Nov 13 |
| Petaluma, CA | 8.1 mi | Feb 28 | Nov 25 |
| Sonoma, CA | 14 mi | Mar 2 | Nov 27 |
| Windsor, CA | 15 mi | Mar 2 | Nov 20 |
| St. Helena, CA | 17 mi | Feb 3 | Dec 4 |
| Novato, CA | 20 mi | Jan 11 | Dec 21 |
| Healdsburg, CA | 21 mi | Feb 15 | Dec 2 |
| Napa, CA | 22 mi | Feb 12 | Dec 4 |
Frequently asked questions
When is the last frost in Rohnert Park?
On average, the last spring frost (32°F) in Rohnert Park 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 Rohnert Park?
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 Rohnert Park 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 Rohnert Park?
Rohnert Park 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 94928. See growing zones in California.
More: all California frost dates · California growing zones · UV index today in Rohnert Park · frost vs. freeze