Santa Rosa in Winter
In winter (December, January and February), Santa Rosa sees average daytime highs around 58°F and overnight lows near 40°F, with 17.4 in of rain over about 30 wet days across the season. It is the coldest season of the year and the wettest season of the year.
Across winter, daytime highs hold fairly steady around 58°F. The sky is clear or mostly clear about 34% of the time across winter, and the air most often feels dry.
Winter is Santa Rosa's weakest season of the year to visit on our travel score. For the whole year in context, see Santa Rosa's year-round climate.
- Avg daytime high
- 58°F
- coldest season of the year
- Avg overnight low
- 40°F
- Rainfall
- 17.4 in
- 30 wet days
- Avg wind
- 4 mph
- Travel score
- 4.2
- weakest season of the year
- Months
- Dec · Jan · Feb
Temperature in Santa Rosa in Winter
Across winter, daytime highs hold fairly steady around 58°F.
A typical winter day in Santa Rosa reaches about 58°F and drops to 40°F overnight. The warmest of the three months is February, the coolest December.
Santa Rosa weather by month
How the three winter months (December, January and February) compare with the rest of the year — the season's months are highlighted.
| Month | High / Low (°F) | Rainfall (inches) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 57° / 40° | 5.7 | 10.3 | 9.6 | 4.0 |
| Feb | 60° / 42° | 5.8 | 9.3 | 10.5 | 4.7 |
| Mar | 63° / 44° | 4.4 | 9.5 | 11.7 | 5.7 |
| Apr | 67° / 46° | 1.9 | 5.6 | 13 | 7.0 |
| May | 73° / 51° | 1.1 | 3.6 | 14.1 | 8.2 |
| Jun | 80° / 55° | 0.3 | 1.2 | 14.6 | 8.5 |
| Jul | 83° / 57° | 0.0 | 0.1 | 14.4 | 7.8 |
| Aug | 83° / 57° | 0.0 | 0.2 | 13.5 | 7.8 |
| Sep | 81° / 55° | 0.1 | 0.6 | 12.3 | 8.6 |
| Oct | 74° / 50° | 1.4 | 3.2 | 11 | 8.5 |
| Nov | 63° / 44° | 3.0 | 6.2 | 9.9 | 6.2 |
| Dec | 56° / 39° | 5.9 | 10.1 | 9.4 | 3.9 |
Cloud cover in Winter
The sky is clear or mostly clear about 34% of the time across winter.
Chance of precipitation in Winter
Santa Rosa gets around 17.4 in of rain over 30 wet days across winter. The line is the day-by-day chance of measurable precipitation.
Humidity in Winter
Most of winter feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Winter
Winds average 4 mph across winter.
Sunrise & sunset in Winter
Daylight runs from about 9 h 30 min in early December to 11 hours by late February. The lit band spans sunrise to sunset each day.
Solar energy in Winter
Average shortwave solar energy reaching the ground each day across winter, about 2.5 kWh/m².
Hazard calendar for Santa Rosa
In winter, Santa Rosa overlaps its rainy season season. The full year is below, with each hazard's peak months called out.
Santa Rosa's rainy season runs November–March, when most of the year's rain falls.
Is winter a good time to visit Santa Rosa?
Our two travel scores rate winter for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
winter is a reasonable time to visit Santa Rosa for sightseeing.
What to pack for Santa Rosa in Winter
From winter's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In winter, Santa Rosa sees daytime highs around 58°F and nights near 40°F. Worth packing: a warm layer and rain gear. About 30 days see rain.
Sea temperature near Santa Rosa in Winter
The nearest coast averages about 53°F across winter — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea at the nearest coast (about 23 mi away) is warmest in September at about 55°F and coldest in May near 51°F.
The water stays below 68°F all year — cool enough that most swimmers want a wetsuit.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°F) | 53 | 53 | 53 | 51 | 51 | 51 | 53 | 54 | 55 | 55 | 54 | 53 |
| Comfort | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing |
| Sea temperature (°F) | Comfort | |
|---|---|---|
| Jan | 53 | Bracing |
| Feb | 53 | Bracing |
| Mar | 53 | Bracing |
| Apr | 51 | Bracing |
| May | 51 | Bracing |
| Jun | 51 | Bracing |
| Jul | 53 | Bracing |
| Aug | 54 | Bracing |
| Sep | 55 | Bracing |
| Oct | 55 | Bracing |
| Nov | 54 | Bracing |
| Dec | 53 | Bracing |
UV index in Santa Rosa in Winter
Clear-sky midday UV across winter averages around 3. The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Santa Rosa peaks around June 23 at about 10 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 17 at about 2 (moderate).
The index reaches 3 or more — the level where the WHO recommends sun protection — in 9 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 2 | 4 | 5 | 6 | 9 | 10 | 10 | 9 | 6 | 5 | 2 | 2 |
| Level | Moderate | Moderate | Moderate | High | Very high | Extreme | Extreme | Very high | High | High | Moderate | Low |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 2 | Moderate |
| Feb | 4 | Moderate |
| Mar | 5 | Moderate |
| Apr | 6 | High |
| May | 9 | Very high |
| Jun | 10 | Extreme |
| Jul | 10 | Extreme |
| Aug | 9 | Very high |
| Sep | 6 | High |
| Oct | 5 | High |
| Nov | 2 | Moderate |
| Dec | 2 | Low |
Air quality in Santa Rosa in Winter
Average fine-particle pollution (PM2.5) through the year — so you can see where winter falls, not just the annual average.
Air quality in Santa Rosa is worst in September — around 24 µg/m³ PM2.5 (moderate), about 4.1× the cleanest month (June, 6 µg/m³).
Modeled monthly averages (CAMS reanalysis, 2015–2024).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 8 | 9 | 9 | 7 | 7 | 6 | 9 | 17 | 24 | 16 | 9 | 7 |
| Level | Good | Good | Good | Good | Good | Good | Good | Moderate | Moderate | Moderate | Good | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 8 | Good |
| Feb | 9 | Good |
| Mar | 9 | Good |
| Apr | 7 | Good |
| May | 7 | Good |
| Jun | 6 | Good |
| Jul | 9 | Good |
| Aug | 17 | Moderate |
| Sep | 24 | Moderate |
| Oct | 16 | Moderate |
| Nov | 9 | Good |
| Dec | 7 | Good |
Where is Santa Rosa?
Santa Rosa sits at 38.4°N, 122.7°W, 164 ft above sea level, in United States. The nearest listed city is Rohnert Park, 6.8 mi away.
Topography around Santa Rosa
How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Santa Rosa.
Within 2 miles, the terrain around Santa Rosa has only modest variations in elevation — a maximum elevation change of 449 ft around an average of 184 ft above sea level; within 10 miles, large variations in elevation — a maximum elevation change of 2,687 ft; within 50 miles, very significant variations in elevation — a maximum elevation change of 4,895 ft.
The land around Santa Rosa is covered by artificial surfaces (65%) and trees (28%) within 2 miles, trees (44%) and grassland (34%) within 10 miles, and trees (38%), water (27%) and grassland (26%) within 50 miles.
United States travel facts
- Power plugs
- Type A / B
- 120 V · 60 Hz
- Prices
- ≈ 100% of US
- price level, 2025
- GDP per capita
- $90,027
- 2025
- Happiness
- 6.8 / 10
- World Happiness, 2025
- Safe drinking water
- 98%
- of population, 2024
- Homicide rate
- 5.8
- per 100k, 2023
- Road deaths
- 12.7
- per 100k/yr, 2019
- Income group
- High
- World Bank
- Religion
Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.
Data sources
Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Santa Rosa (38.4405°, -122.7144°, elevation 164 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google.