Frost Dates for Windsor, CA

Based on data from Santa Rosa Sonoma Co AP weather station, 3 miles away

Frost Dates

Last Spring Frost (50%) iA 50% chance that the last spring frost has already passed by this date. Most gardeners use this as their primary planting guide. March 2
First Fall Frost (50%) iA 50% chance that the first fall frost has occurred by this date. Plan to harvest or protect tender plants before this date. November 20
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

30% Probability iOnly a 30% chance of frost remaining by this date. Use these dates for a safer planting window, especially for tender plants sensitive to cold.

Last Spring Frost March 14
First Fall Frost November 12

Hard Freeze (28°F)

Last Spring Hard Freeze January 23
First Fall Hard Freeze December 5
38.55°N, -122.82°W © OpenStreetMap

Growing Season

263 Days March 2 to November 20

USDA Hardiness Zone iHardiness zones indicate which perennial plants can survive winter in your area. For annual vegetables, frost dates and growing season length matter more than hardiness zone.

Zone 9a

Avg. annual minimum: 20 to 25°F (−7 to −4°C)

Learn more

Köppen Climate iThe Köppen climate classification system categorizes climates based on temperature and precipitation patterns.

Csb Warm-Summer Mediterranean

Warm, dry summers and mild, wet winters. Similar to hot-summer Mediterranean but cooler. Great for a wide range of vegetables and fruit trees with moderate water needs.

Köppen climate map

Temperature

30° 50° 70° 90°
48°
High: 58°F
Avg: 48°F
Low: 38°F
Jan
51°
High: 62°F
Avg: 51°F
Low: 39°F
Feb
53°
High: 65°F
Avg: 53°F
Low: 41°F
Mar
56°
High: 69°F
Avg: 56°F
Low: 43°F
Apr
61°
High: 75°F
Avg: 61°F
Low: 47°F
May
66°
High: 82°F
Avg: 66°F
Low: 50°F
Jun
68°
High: 84°F
Avg: 68°F
Low: 52°F
Jul
68°
High: 84°F
Avg: 68°F
Low: 52°F
Aug
67°
High: 83°F
Avg: 67°F
Low: 50°F
Sep
61°
High: 77°F
Avg: 61°F
Low: 46°F
Oct
53°
High: 65°F
Avg: 53°F
Low: 40°F
Nov
47°
High: 58°F
Avg: 47°F
Low: 37°F
Dec
32°F
Avg High Avg Temp Avg Low Light Frost (32°F)

Precipitation

0" 3" 6" 8.2"
7.3"
7.27"
Jan
7.3"
7.26"
Feb
6.5"
6.49"
Mar
4.2"
4.23"
Apr
2.5"
2.46"
May
0.0"
0.00"
Jun
0.0"
0.00"
Jul
0.0"
0.00"
Aug
0.0"
0.00"
Sep
3.7"
3.69"
Oct
5.6"
5.57"
Nov
8.2"
8.15"
Dec

Sunrise / Sunset

4a7a10a1p4p7p10pNoonJanFebMarAprMayJunJulAugSepOctNovDec9.5h10.5h11.5h13h14h14.5h14.5h13.5h12h11h10h9.5h
Jan: 7:12 AM – 4:48 PM · 9h 36m
Feb: 6:43 AM – 5:17 PM · 10h 33m
Mar: 6:09 AM – 5:51 PM · 11h 42m
Apr: 5:30 AM – 6:30 PM · 13h 01m
May: 4:57 AM – 7:03 PM · 14h 06m
Jun: 4:40 AM – 7:20 PM · 14h 40m
Jul: 4:47 AM – 7:13 PM · 14h 26m
Aug: 5:15 AM – 6:45 PM · 13h 30m
Sep: 5:53 AM – 6:07 PM · 12h 14m
Oct: 6:31 AM – 5:29 PM · 10h 58m
Nov: 7:04 AM – 4:56 PM · 9h 52m
Dec: 7:20 AM – 4:40 PM · 9h 19m
Daylight Longest: 14h 41m · Shortest: 9h 19m

Nearby Stations

Graton, CAMarch 20 - November 13 Santa Rosa, CA February 25 - December 1 Healdsburg, CA February 15 - December 2 Occidental, CA January 29 - December 30 Calistoga, CA March 2 - November 23 Saint Helena, CA February 3 - December 4

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