Petaluma, CA Climate: Temperature & Rain by Month
Pulled from NOAA NCEI 1991–2020 normals →: climate measurements used in PlainClimate's documented score
30-year climate normals (1991-2020) from Petaluma's primary NOAA station, PETALUMA AP.
The climate verdict for Petaluma
A compact 18.9°F seasonal swing gives Petaluma, California a steadier-than-extreme annual shape. NOAA reports an annual average of 58°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.
- 58°F
- average temperature, NOAA 1991-2020 normal
- 87/100
- comfort score, above 87% of station-mapped location scores
- 25.6"
- yearly precipitation total
- 270 days
- frost-free days per growing season
Petaluma: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USC00046826 · Petaluma, CA 58°F mean · 25.6" precip
TEMP-MILD · RANK-UPPER · PHOTO-FINISH · PRCP-MID · SWING-NARROW · COMF-TOP · LOAD-HEAT · STN-1 · BOOK-FULL
- TEMP-MILD 58°F
- RANK-UPPER #4,734
- PHOTO-FINISH ≈ Santa Rosa Sono…
- PRCP-MID 25.6"
- SWING-NARROW 19°F
- COMF-TOP 87/100
- LOAD-HEAT 2,853 HDD
- STN-1 USC00046826
- BOOK-FULL 6/6 fields
Nearest mean-temperature peer: Santa Rosa Sonoma County, CA (+ 0.1 °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.
- Petaluma (this station) 58°F
- Cold Napa County, CA 58°F
- Hot Carmel Valley, CA 58°F
- Near Santa Rosa Sono…, CA 58°F
- Near Graton, CA 58°F
Climate Living Index · Petaluma
Petaluma: 83/100 · grade B
Petaluma publishes 5 of 6 Living Index dimensions (NOAA annual/seasonal normals · NOAA daily multivariate normals); 1 missing weight rescale to 100.
PlainClimate-derived for Petaluma, 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 | 270 days/year | 94/100 · A |
| Snowfall burden | 0.0 inches/year | 90/100 · A |
| Annual temperature balance | 58.0°F · 9.5° from 67.5°F | 70/100 · B |
| Precipitation balance | 25.6 in · 9.4 from 35 in | 67/100 · C |
Petaluma · 2026-08-04 · NOAA NCEI Climate Normals · method · Comfort Score method.
Petaluma is a temperate Köppen climate: Csb
Coldest-month mean 48.1°F and warmest-month mean 67.0°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
- 67.0°F
- Coldest month
- 48.1°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 Petaluma sits across the climate record
Three NOAA fields for Petaluma's primary station, temperature, precipitation, and seasonal swing, are ranked against every station-mapped normal that carries the same field.
- Annual temperature
- 69th percentile warmth
- Mid-pack annual mean versus 6,861 station normals.
- Annual precipitation
- 35th percentile wetness
- Neither arid nor torrential versus 6,352 station totals.
- Seasonal temperature swing
- Narrower than 97%
- Warmest-to-coldest month gap for Petaluma is compact versus 6,861 complete station-years.
How Petaluma compares across U.S. station-mapped locations
Petaluma'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
Petaluma's measured station temperature trend
MethodologyAcross 72 complete annual observations from 1914 to 2025, PETALUMA AP warmed at a fitted rate of 0.16°C per decade. The line shows the fitted change relative to its first year, not raw year-to-year temperatures or a forecast.
- Petaluma primary station fitted change +0.16 °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 | 58°F (14°C) | 39°F (4°C) | 48°F (9°C) | 4.8" | 0.0" | 6.1 | 0.0 |
| February | 61°F (16°C) | 40°F (5°C) | 51°F (10°C) | 5.2" | 0.0" | 3.2 | 0.0 |
| March | 65°F (18°C) | 42°F (5°C) | 53°F (12°C) | 3.3" | 0.0" | 0.8 | 0.0 |
| April | 68°F (20°C) | 44°F (7°C) | 56°F (13°C) | 1.7" | 0.0" | 0.5 | 0.1 |
| May | 72°F (22°C) | 47°F (9°C) | 60°F (15°C) | 0.9" | 0.0" | 0.0 | 0.9 |
| June | 78°F (26°C) | 50°F (10°C) | 64°F (18°C) | 0.3" | 0.0" | 0.0 | 2.9 |
| July | 81°F (27°C) | 52°F (11°C) | 67°F (19°C) | 0.0" | 0.0" | 0.0 | 3.7 |
| August | 81°F (27°C) | 53°F (12°C) | 67°F (19°C) | 0.1" | 0.0" | 0.0 | 4.4 |
| September | 82°F (28°C) | 51°F (11°C) | 67°F (19°C) | 0.1" | 0.0" | 0.0 | 6.4 |
| October | 76°F (25°C) | 48°F (9°C) | 62°F (17°C) | 1.3" | 0.0" | 0.0 | 2.2 |
| November | 66°F (19°C) | 42°F (6°C) | 54°F (12°C) | 2.7" | 0.0" | 2.8 | 0.0 |
| December | 58°F (14°C) | 38°F (4°C) | 48°F (9°C) | 5.2" | 0.0" | 7.6 | 0.0 |
The year, day by day
The calendar barely moves in Petaluma: no date carries a normal high of 90°F or a normal low at freezing. The year runs between 38°F near December 18 and 82°F near September 5.
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 18.
Where the wet dates fall
The likeliest wet date is January 1, when 39% of years recorded at least a hundredth of an inch. The driest is July 25 at 1%. Summed across the calendar, that is about 70 wet dates a year.
The widest day
September 18 carries the biggest normal gap between afternoon and dawn, 30°F between the normal high and the normal low.
Look up any date
Any date's 1991–2020 normal for Petaluma.
Monthly Precipitation
Average monthly rainfall and snowfall
12.0 days with precipitation
11.0 days with precipitation
10.2 days with precipitation
6.4 days with precipitation
3.7 days with precipitation
1.3 days with precipitation
0.1 days with precipitation
0.3 days with precipitation
1.0 days with precipitation
3.6 days with precipitation
7.8 days with precipitation
12.1 days with precipitation
Petaluma'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 18.9°F seasonal spread.
- Wettest month
- February, 5.2"
- Driest month
- July, 0.0"
- Wettest three months
- February, December, 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 Petaluma, it arrives in quantity
25.6" of precipitation falls across only about 70 wet days here, averaging 0.37 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 70 a year, 19% of all days
- Average depth per wet day
- 0.37 inches
- Most wet days
- December, about 12
- 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.
Petaluma'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
November 25
50% probability date
Last Spring Freeze
February 28
50% probability date
Growing Season
270 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
2,853
Higher = more heating needed
Cooling Degree Days
317
Higher = more cooling needed
Warmest Month
August
Coldest Month
December
Nationwide similar cities
Other rankable U.S. places outside CA closest to Petaluma 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 (58°F here).
- Bartlesville, OK 58°F · 0.0°F off
- Columbia, TN 58°F · 0.0°F off
- Disputanta, VA 58°F · 0.0°F off
- Hot Springs, NC 58°F · 0.0°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (25.6" here), excluding temperature-peer places.
- Kearney, NE 25.6" · 0.0" off
- Quanah, TX 25.6" · 0.0" off
- Tilden, TX 25.6" · 0.0" off
- Phillipsburg, KS 25.6" · 0.1" off
Data-derived climate profile
How Petaluma's climate pattern fits together
heating led · moderate · low swing
Heating is the larger measured load in Petaluma, at 2,853 degree days versus 317 for cooling. Unlike a strongly continental record, however, its 18.9°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 270 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 18.9°F band across the normal year. August and December mark the typical warm and cold ends of the calendar. The annual average is 58°F. Monthly rows still matter, but they refine a steady profile rather than reveal two climatic extremes.
Petaluma's 25.6 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 Petaluma'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 Petaluma, not an official NOAA class or a year-ahead forecast.
Questions about Petaluma's climate
How much rain does Petaluma get? ▼
How much energy does heating and cooling require in Petaluma? ▼
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from Petaluma's primary station: PETALUMA AP (USC00046826). 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 0656784). Match rule for Petaluma: 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 Petaluma 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.