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Will it freeze in Grass Valley in the next 7 nights?
No overnight lows at or below 32°F are forecast in Grass Valley during the next 7 nights in the available NWS frost forecast.
Tonight: forecast low 44°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 44°F Above 36°F · Mostly Clear
- Fri, Nov 6 45°F Above 36°F · Mostly Clear
- Sat, Nov 7 47°F Above 36°F · Mostly Clear
- Sun, Nov 8 46°F Above 36°F · Partly Cloudy
- Mon, Nov 9 45°F Above 36°F · Mostly Clear
- Tue, Nov 10 47°F Above 36°F · Partly Cloudy then Slight Chance Light Rain
- Wed, Nov 11 46°F Above 36°F · Slight 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 Grass Valley
The median first fall hard-freeze date (28°F) is December 1, from NOAA’s 1991–2020 Climate Normals at Grass Valley #2. 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 13 · Apr 28 · May 20 | Oct 11 · Oct 31 · Nov 13 | 182 days |
| 32°F freeze | Mar 17 · Apr 10 · Apr 30 | Oct 26 · Nov 13 · Dec 1 | 215 days |
| 28°F hard freeze | Jan 31 · Mar 9 · Apr 8 | Nov 11 · Dec 1 · Dec 21 | 268 days |
Average high temperature by month
1991–2020 normals at Grass Valley #2
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 Grass Valley, CA come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Grass Valley #2 (station USC00043573, elevation 2,400 ft), 1.4 mi from Grass Valley. 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 Grass Valley
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| Auburn, CA | 22 mi | Feb 25 | Dec 5 |
| Lincoln, CA | 27 mi | Feb 25 | Dec 5 |
| Marysville, CA | 29 mi | Jan 15 | Dec 12 |
| Loomis, CA | 29 mi | Feb 25 | Dec 5 |
| Rocklin, CA | 30 mi | Feb 25 | Dec 5 |
| Yuba City, CA | 32 mi | Jan 15 | Dec 12 |
| Live Oak, CA | 33 mi | Jan 15 | Dec 12 |
| Oroville, CA | 33 mi | Jan 30 | Dec 13 |
| Roseville, CA | 34 mi | Feb 22 | Nov 24 |
| Gridley, CA | 36 mi | Jan 29 | Dec 7 |
Frequently asked questions
When is the last frost in Grass Valley?
On average, the last spring frost (32°F) in Grass Valley 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 17.
When is the first frost in Grass Valley?
The first fall frost (32°F) usually arrives around November 13. There’s a 10% chance of a freeze by October 26 and a 90% chance by December 1.
Can it frost in Grass Valley 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 28.
What growing zone is Grass Valley?
Grass Valley 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 95945. See growing zones in California.
More: all California frost dates · California growing zones · frost vs. freeze