Photo: Stephen Gold · Public domainSebastopol has cooler summers than 93% of U.S. towns
The depth of winter brings overnight lows near 39°. Expect the heaviest rain or snow in December and the lightest in July. In January, nights here are milder than in 87% of U.S. towns. Tender plants can go out after about March 20; in half of years the first frost comes by November 13.
A year in Sebastopol at a glance
Each month’s typical high and low, and what it brings.
What stands out about Sebastopol’s climate
Compared with towns across the U.S., with Sebastopol’s place in California beside it.
What a year in Sebastopol feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 240 frost-free days a year
In half of years the last 32° night comes by March 20 and the first by November 13. Frost and day counts come from NOAA’s station at Graton, CA, 2.9 miles from the town’s center, at about the same height.
The 2023 USDA map puts Sebastopol’s center in zone 9a: the coldest night of a typical winter, averaged over 1991–2020, reaches about 23°. 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 34 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 Sebastopol
90% 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 Graton, CA.
Living with Sebastopol’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
240 frost-free days in zone 9a. The last frost comes by Mar 20 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 13.
Months with highs of 62–84° and lows of 40° or more: March, April, May, June, July, August, September, October and November. 5.7 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Sebastopol from natural hazards, earthquakes are the largest share (68%). Normals are averages; the hazards page covers the extremes.
Natural hazards →Sebastopol and its neighbors
Santa Rosa has the coldest January nights next door (38°, 1° colder) and Santa Rosa the hottest July afternoons (84°, 4° warmer). Differences under a degree are within what the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Sebastopol’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 |
|---|---|---|---|---|
| Sebastopol, CA | 39° | 80° | 34" | 0.0" |
| Tualatin, OR | 36° | 81° | 40" | 1.0" |
| Felida, WA | 35° | 81° | 42" | 0.8" |
| Makawao, HI | 53° | 75° | 23" | 0.0" |
| Swannanoa, NC | 27° | 83° | 48" | 2.1" |
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value. Snow and frost-free days come from the nearest weather station, so neighbors often share them.
Warmer than it used to be
The last 30 years in Sebastopol averaged 1.4° warmer than the 1900s. The biggest change is in January (+2.2°).
A bigger shift than in 54% 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 Sebastopol compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Sebastopol’s place among California’s.
Sebastopol weather by month
Highs, lows and precipitation from NOAA’s grid at Sebastopol’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 | 58° | 39° | 6.5" | 0.0" | 13 | 0 | 45° – 52° |
| February | 62° | 41° | 6.5" | 0.0" | 12 | 0 | 47° – 56° |
| March | 65° | 42° | 4.5" | 0.0" | 11 | 0 | 47° – 58° |
| April | 68° | 43° | 2.2" | 0.0" | 7 | 0 | 51° – 59° |
| May | 73° | 47° | 1.1" | 0.0" | 4 | 0 | 56° – 64° |
| June | 78° | 49° | 0.3" | 0.0" | 2 | 0 | 61° – 67° |
| July | 80° | 51° | 0.0" | 0.0" | 0 | 0 | 62° – 68° |
| August | 81° | 51° | 0.0" | 0.0" | 1 | 0 | 63° – 70° |
| September | 81° | 50° | 0.1" | 0.0" | 2 | 0 | 62° – 69° |
| October | 76° | 47° | 1.6" | 0.0" | 4 | 0 | 58° – 66° |
| November | 65° | 42° | 3.6" | 0.0" | 9 | 0 | 47° – 58° |
| December | 58° | 38° | 7.0" | 0.0" | 13 | 0 | 45° – 53° |
| Year | 70° | 45° | 33.5" | 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 47° to 58°. July is the most reliable, staying within 6°.
Where Sebastopol’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 Sebastopol’s center.
- Snow: Graton, CA.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Graton, CA, 2.9 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 Sebastopol’s climate
What is the weather like in Sebastopol?
A typical July afternoon reaches 80°, a January night drops to 39°, and snow is almost unheard of. Milder January nights than 87% of U.S. towns; cooler July afternoons than 93% of U.S. towns.
How cold does it get in Sebastopol in winter?
December nights average 38°. About 43 nights a year reach 32° or below. In the coldest December of the last 30 years the month averaged 45°.
How much snow does Sebastopol get?
About 0.0 inches in a normal winter at Graton, CA, so most winters see none.
How hot does it get in Sebastopol?
July, with a typical high of 80° and a low of 51°. About 34 days a year reach 90° and 5 reach 100° (Graton, CA).
When is the first and last frost in Sebastopol?
In half of years the last spring frost (32°) comes by March 20 and the first fall frost by November 13, about 240 frost-free days, at Graton, CA.
What growing zone is Sebastopol in?
Zone 9a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 23°.
What is the best time of year to visit Sebastopol?
By one simple rule (highs of 62–84° and lows of 40° or more), March, April, May, June, July, August, September, October and November. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Sebastopol getting warmer?
Yes: 1991–2020 averaged 1.4° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 54% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Sebastopol.
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.