Santa Rosa, CA Climate: Temperature & Rain by Month
Temperature and precipitation from NOAA NCEI 1991–2020 normals →, plus PlainClimate's derived comfort score
30-year climate normals (1991-2020) from Santa Rosa's primary NOAA station, SANTA ROSA.
The climate verdict for Santa Rosa
A compact 19.1°F seasonal swing gives Santa Rosa, California a steadier-than-extreme annual shape. NOAA reports an annual average of 59°F. It scores 87/100 for climate comfort (excellent), putting it in the top third of station-mapped location scores and exceeding 87% of them.
- 59°F
- yearly average temperature, NOAA normal
- 87/100
- comfort score, above 87% of station-mapped location scores
- 31.5"
- annual precipitation
- 279 days
- growing season, frost-free days
Santa Rosa: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USC00047965 · Santa Rosa, CA 59°F mean · 31.5" precip
TEMP-MILD · RANK-UPPER · PHOTO-FINISH · PRCP-MID · SWING-NARROW · COMF-TOP · LOAD-HEAT · STN-1 · BOOK-FULL
- TEMP-MILD 59°F
- RANK-UPPER #4,940
- PHOTO-FINISH ≈ Kentfield
- PRCP-MID 31.5"
- SWING-NARROW 19°F
- COMF-TOP 87/100
- LOAD-HEAT 2,627 HDD
- STN-1 USC00047965
- BOOK-FULL 6/6 fields
Nearest mean-temperature peer: Kentfield, CA (+ 0.2 °F mean)
Instrument codes from this station's NOAA 1991–2020 normals, mean temperature, corpus warmth rank, photo-finish peer station, precipitation band, seasonal swing, comfort composite, degree-day load, and field book, not a livability rating.
Mean-temperature neighbourhood
Nationwide NOAA normal poles and nearest peers, not a reprint of every CA station list.
- Santa Rosa (this station) 59°F
- Cold Palo Alto, CA 59°F
- Hot Redwood City, CA 59°F
- Near Kentfield, CA 59°F
- Near Hollister, CA 59°F
Climate Living Index · Santa Rosa
Santa Rosa: 88/100 · grade A
Santa Rosa publishes 5 of 6 Living Index dimensions (NOAA annual/seasonal normals · NOAA daily multivariate normals); 1 missing weight rescale to 100.
PlainClimate-derived for Santa Rosa, not an official NOAA rating. Rankings still use Comfort Score 87/100 (separate formula). Breakpoints and limits.
| Dimension | Station value | Score |
|---|---|---|
| Normal heat + freeze calendar | 0 calendar days | 100/100 · A |
| Frost-free season | 279 days/year | 97/100 · A |
| Snowfall burden | 0.0 inches/year | 90/100 · A |
| Precipitation balance | 31.5 in · 3.5 from 35 in | 87/100 · A |
| Annual temperature balance | 59.0°F · 8.5° from 67.5°F | 73/100 · B |
Santa Rosa · 2026-08-04 · NOAA NCEI Climate Normals · method · Comfort Score method.
Santa Rosa is a temperate Köppen climate: Csb
Coldest-month mean 48.6°F and warmest-month mean 67.7°F place this station in temperate, dry-summer, warm summer climates (Csb). Class Csb is the Peel et al. (2007) label for this station's monthly mean temperature and precipitation normals: temperate, specifically temperate, dry-summer, warm summer.
- Köppen code
- Csb
- Group
- Temperate
- Warmest month
- 67.7°F
- Coldest month
- 48.6°F
Source: official public datasets monthly normals (1991–2020) at the city’s primary station. This is a station classification, not a mapped regional consensus.
National standing · heating-led station
Where Santa Rosa sits across the climate record
Three NOAA fields for Santa Rosa's primary station, temperature, precipitation, and seasonal swing, are ranked against every station-mapped normal that carries the same field.
- Annual temperature
- Top 28% warmest
- Among 6,861 stations, Santa Rosa sits in the warmer third of annual means.
- Annual precipitation
- 42nd percentile wetness
- Neither arid nor torrential versus 6,352 station totals.
- Seasonal temperature swing
- Narrower than 97%
- Warmest-to-coldest month gap for Santa Rosa is compact versus 6,861 complete station-years.
How Santa Rosa compares across U.S. station-mapped locations
Santa Rosa's comfort score vs. all station-mapped locations
PlainClimate composite comfort index (1–100), NOAA 1991–2020 normals
87 Top 13% score exceeds 87% of 6,189 station-mapped location scores
- 0–10: 0 station-mapped locations (0%). Below this entry.
- 10–20: 0 station-mapped locations (0%). Below this entry.
- 20–30: 96 station-mapped locations (2%). Below this entry.
- 30–40: 280 station-mapped locations (5%). Below this entry.
- 40–50: 1,113 station-mapped locations (18%). Below this entry.
- 50–60: 1,329 station-mapped locations (21%). Below this entry.
- 60–70: 1,236 station-mapped locations (20%). Below this entry.
- 70–80: 650 station-mapped locations (11%). Below this entry.
- 80–90: 921 station-mapped locations (15%). This entry sits in this band.
- 90–100: 564 station-mapped locations (9%). Above this entry.
Source NOAA U.S. Climate Normals, PlainClimate comfort index · 1991–2020
Santa Rosa's measured station temperature trend
MethodologyAcross 83 complete annual observations from 1892 to 2021, SANTA ROSA warmed at a fitted rate of 0.14°C per decade. The line shows the fitted change relative to its first year, not raw year-to-year temperatures or a forecast.
- Santa Rosa primary station fitted change +0.14 °C/decade
Monthly Temperatures
Average daily high and low temperatures by month
| Month | Avg High | Avg Low | Mean | Precip | Snow | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|---|
| January | 60°F (15°C) | 38°F (4°C) | 49°F (10°C) | 5.8" | 0.0" | 4.3 | 0.0 |
| February | 64°F (18°C) | 40°F (4°C) | 52°F (11°C) | 6.4" | 0.0" | 2.5 | 0.0 |
| March | 67°F (19°C) | 42°F (5°C) | 54°F (12°C) | 4.3" | 0.0" | 0.5 | 0.0 |
| April | 71°F (21°C) | 44°F (7°C) | 57°F (14°C) | 2.0" | 0.0" | 0.0 | 0.4 |
| May | 75°F (24°C) | 48°F (9°C) | 61°F (16°C) | 1.3" | 0.0" | 0.0 | 0.7 |
| June | 80°F (27°C) | 51°F (11°C) | 66°F (19°C) | 0.3" | 0.0" | 0.0 | 4.5 |
| July | 82°F (28°C) | 52°F (11°C) | 67°F (19°C) | 0.0" | 0.0" | 0.0 | 4.0 |
| August | 83°F (28°C) | 53°F (11°C) | 68°F (20°C) | 0.0" | 0.0" | 0.0 | 6.1 |
| September | 84°F (29°C) | 51°F (11°C) | 68°F (20°C) | 0.1" | 0.0" | 0.0 | 7.3 |
| October | 79°F (26°C) | 48°F (9°C) | 63°F (17°C) | 1.6" | 0.0" | 0.0 | 2.7 |
| November | 67°F (19°C) | 42°F (6°C) | 55°F (13°C) | 3.3" | 0.0" | 2.0 | 0.0 |
| December | 59°F (15°C) | 38°F (3°C) | 49°F (9°C) | 6.5" | 0.0" | 5.5 | 0.0 |
The year, day by day
The calendar barely moves in Santa Rosa: no date carries a normal high of 90°F or a normal low at freezing. The year runs between 38°F near December 22 and 85°F near September 4.
No freezing date
Not one calendar date in the 1991–2020 record carries a normal low at or below 32°F. The coldest normal low of the year is 38°F around December 22.
Where the wet dates fall
The likeliest wet date is January 23, when 46% of years recorded at least a hundredth of an inch. The driest is July 14 at 1%. Summed across the calendar, that is about 81 wet dates a year.
The widest day
September 18 carries the biggest normal gap between afternoon and dawn, 33°F between the normal high and the normal low.
Look up any date
Any date's 1991–2020 normal for Santa Rosa.
Where Santa Rosa Stands Nationally
Daily temperature swings run wider than most of the country, peaking near 33°F between the normal high and low.
Santa Rosa earns one nationally notable standing (outer quintile) against 6,860 NOAA 1991–2020 normals stations, middle-of-the-pack metrics stay silent here.
Monthly Precipitation
Average monthly rainfall and snowfall
14.2 days with precipitation
12.7 days with precipitation
12.2 days with precipitation
7.8 days with precipitation
5.2 days with precipitation
1.3 days with precipitation
0.3 days with precipitation
0.4 days with precipitation
1.3 days with precipitation
3.7 days with precipitation
9.2 days with precipitation
13.1 days with precipitation
Santa Rosa's wet season runs through the cold months
December, January and February carry 59% of the year's precipitation here, while June through August contribute 1%. That is the cool-season-dominant pattern of the West Coast and the higher inland West, where storm tracks swing south in winter and summer turns dry; the thermometer meanwhile shows an unusually narrow 19.1°F seasonal spread.
- Wettest month
- December, 6.5"
- Driest month
- July, 0.0"
- Wettest three months
- December, February, January (59% of the year)
Shares are computed from this station's own 1991-2020 monthly precipitation normals. A cool-season label means the December-February share reaches 35%. Where snow falls, the monthly figures above report liquid-equivalent precipitation, so a wet winter month is not necessarily a rainy one.
When it rains in Santa Rosa, it arrives in quantity
31.5" of precipitation falls across only about 81 wet days here, averaging 0.39 inches each. Fewer days carry more water: the year's total is delivered in comparatively heavy events rather than persistent damp.
- Days with measurable precipitation
- about 81 a year, 22% of all days
- Average depth per wet day
- 0.39 inches
- Most wet days
- January, about 14
- Fewest wet days
- July, about 0
A wet day is one recording at least 0.01 inches. These are 1991-2020 normals: they describe an average year, and a per-day average is not a forecast of any individual storm.
Santa Rosa's record shows no measurable snowfall
This station measured snowfall across the 1991-2020 period and recorded none: the annual normal is 0.0 inches. That is a measured zero rather than missing data, which is a meaningful distinction here , most stations in the database simply do not report snow at all, and those pages say nothing about it.
A thirty-year normal of zero describes the typical year at this station. It is not a claim that snow has never fallen in the area.
Frost Dates & Growing Season
First Fall Freeze
December 1
50% probability date
Last Spring Freeze
February 25
50% probability date
Growing Season
279 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
2,627
Higher = more heating needed
Cooling Degree Days
442
Higher = more cooling needed
Warmest Month
August
Coldest Month
December
Nationwide similar cities
Other rankable U.S. places outside CA closest to Santa Rosa on two NOAA annual-normal axes (mean temperature and annual precipitation). Chip rows use distinct link sets.
Closest by average temperature
Nearest out-of-state peers by annual mean temperature (59°F here).
- Asheboro, NC 59°F · 0.0°F off
- Claremore, OK 59°F · 0.0°F off
- Elida, NM 59°F · 0.0°F off
- Gadsden, AL 59°F · 0.0°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (31.5" here), excluding temperature-peer places.
- Pleasanton, TX 31.5" · 0.0" off
- Moose Lake, MN 31.5" · 0.0" off
- Weston, NE 31.6" · 0.0" off
- Ripon, WI 31.5" · 0.1" off
Data-derived climate profile
How Santa Rosa's climate pattern fits together
heating led · moderate · low swing
Heating is the larger measured load in Santa Rosa, at 2,627 degree days versus 442 for cooling. Unlike a strongly continental record, however, its 19.1°F month-to-month range is compact; persistent cool-season demand matters more than a dramatic summer-to-winter reversal.
The frost-free window extends for about 279 days. That is a long calendar measure, but it is not a forecast and does not combine heat, rainfall, soil, or local elevation into a planting recommendation.
Temperature varies within a narrow 19.1°F band across the normal year. August and December mark the typical warm and cold ends of the calendar. The annual average is 59°F. Monthly rows still matter, but they refine a steady profile rather than reveal two climatic extremes.
Santa Rosa's 31.5 inches of annual precipitation falls in PlainClimate's middle band, so “wet” or “dry” is not the leading description. Recorded annual snowfall is negligible. Temperature balance and the calendar distribution carry more information than the annual moisture label alone.
These labels group NOAA 1991-2020 normals from Santa Rosa's primary station, so the winter figures are a thirty-year average and not a floor: a single hard season can run well below them. Treat each band as a descriptive range for Santa Rosa, not an official NOAA class or a year-ahead forecast.
Questions about Santa Rosa's climate
How much rain does Santa Rosa get? ▼
How much energy does heating and cooling require in Santa Rosa? ▼
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from Santa Rosa's primary station: SANTA ROSA (USC00047965). For informational purposes only.
Place identity: U.S. Census Bureau 2024 Gazetteer places. The 2024 Census Gazetteer identifies the exact name-and-state match as an incorporated place (GEOID 0670098). Match rule for Santa Rosa: exact normalized name + state only, no fuzzy expansion, so nearby differently spelled facilities stay unmatched.
On this page every temperature, precipitation, and derived score for Santa Rosa comes from its primary NOAA station record. No figure on this page is typed in by an editor - each value is rendered from NOAA 1991-2020 U.S. Climate Normals. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 1991–2020 normals.