James H. and Frances E. Laughlin House · Photo: Sanfranman59 · CC BY-SA 3.0Windsor’s winters are milder and less snowy than most of the U.S.
A typical July afternoon reaches 85°, a January night drops to 38°, and snow is almost unheard of.
A year in Windsor at a glance
Each month’s typical high and low, and what it brings.
What stands out about Windsor’s climate
Compared with towns across the U.S., with Windsor’s place in California beside it.
What a year in Windsor feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 262 frost-free days a year
In half of years the last 32° night comes by March 2 and the first by November 20. Frost and day counts come from NOAA’s station at Santa Rosa Sonoma Co Airport, 2.7 miles from the town’s center, at about the same height.
The 2023 USDA map puts Windsor’s center in zone 9a: the coldest night of a typical winter, averaged over 1991–2020, reaches about 24°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
About 35 inches of rain a year
December is the wettest month and July the driest. Rain falls on about 78 days a year. Snow is rare: about 0.0" in a normal year at Graton, CA, so most winters see none.
Rain + melted snow by month
Inches of water
Heating and cooling a home in Windsor
88% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from November through March.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Santa Rosa Sonoma Co Airport.
Living with Windsor’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
262 frost-free days in zone 9a. The last frost comes by Mar 2 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Nov 20.
Months with highs of 62–84° and lows of 40° or more: February, March, April, May, June, September, October and November. 17 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Windsor from natural hazards, earthquakes are the largest share (53%); heat waves, cold waves, winter storms and ice storms together are 1%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Windsor and similar climates
TownRatings has no climate map of the towns around Windsor yet.
Climates most like Windsor’s, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| Windsor, CA | 38° | 85° | 35" | 0.0" |
| Roseburg, OR | 37° | 86° | 34" | 0.0" |
| Felida, WA | 35° | 81° | 42" | 0.8" |
| Kill Devil Hills, NC | 35° | 86° | 50" | 1.1" |
| Port Lavaca, TX | 46° | 91° | 40" | 0.0" |
Temperatures and precipitation come from NOAA’s 5 km grid; snow and day counts from the stations named on this page.
Warmer than it used to be
The last 30 years in Windsor averaged 1.5° warmer than the 1900s. The biggest change is in January (+2.3°).
A bigger shift than in 61% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How Windsor compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Windsor’s place among California’s.
Windsor weather by month
Highs, lows and precipitation from NOAA’s grid at Windsor’s center; snow, wet days and snow on the ground from Graton, CA. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 59° | 38° | 6.9" | 0.0" | 13 | 0 | 45° – 53° |
| February | 62° | 40° | 6.6" | 0.0" | 12 | 0 | 46° – 57° |
| March | 66° | 41° | 4.9" | 0.0" | 11 | 0 | 48° – 59° |
| April | 70° | 43° | 2.3" | 0.0" | 7 | 0 | 51° – 60° |
| May | 76° | 47° | 1.3" | 0.0" | 4 | 0 | 56° – 66° |
| June | 82° | 51° | 0.3" | 0.0" | 2 | 0 | 63° – 69° |
| July | 85° | 52° | 0.0" | 0.0" | 0 | 0 | 66° – 72° |
| August | 85° | 52° | 0.0" | 0.0" | 1 | 0 | 66° – 72° |
| September | 84° | 50° | 0.1" | 0.0" | 2 | 0 | 64° – 71° |
| October | 77° | 47° | 1.7" | 0.0" | 4 | 0 | 59° – 68° |
| November | 66° | 41° | 3.6" | 0.0" | 9 | 0 | 47° – 57° |
| December | 58° | 38° | 7.0" | 0.0" | 13 | 0 | 44° – 52° |
| Year | 72° | 45° | 34.5" | 0.0" | 78 | 0 |
How much a month can swing
A normal is an average. March swings the most: from 1991 to 2020 its average ranged from 48° to 59°. June is the most reliable, staying within 6°.
Where Windsor’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at Windsor’s center.
- Snow: Graton, CA.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Santa Rosa Sonoma Co Airport, 2.7 miles from the town’s center, at about the same height; the nearest station that passes our checks for distance, height and agreement with the grid.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about Windsor’s climate
What is the weather like in Windsor?
A typical July afternoon reaches 85°, a January night drops to 38°, and snow is almost unheard of. Milder January nights than 86% of U.S. towns; cooler July afternoons than 55% of U.S. towns.
How cold does it get in Windsor in winter?
December nights average 38°. About 31 nights a year reach 32° or below. In the coldest December of the last 30 years the month averaged 44°.
How much snow does Windsor get?
About 0.0 inches in a normal winter at Graton, CA, so most winters see none.
How hot does it get in Windsor?
July, with a typical high of 85° and a low of 52°. About 34 days a year reach 90° and 4 reach 100° (Santa Rosa Sonoma Co Airport).
When is the first and last frost in Windsor?
In half of years the last spring frost (32°) comes by March 2 and the first fall frost by November 20, about 262 frost-free days, at Santa Rosa Sonoma Co Airport.
What growing zone is Windsor in?
Zone 9a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 24°.
What is the best time of year to visit Windsor?
By one simple rule (highs of 62–84° and lows of 40° or more), February, March, April, May, June, September, October and November. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Windsor getting warmer?
Yes: 1991–2020 averaged 1.5° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 61% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Windsor.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.