Graton, 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 Graton's primary NOAA station, GRATON.
The climate verdict for Graton
A compact 19.9°F seasonal swing gives Graton, California a steadier-than-extreme annual shape. NOAA reports an annual average of 58°F. It scores 83/100 for climate comfort (excellent), putting it in the top third of station-mapped location scores and exceeding 81% of them.
- 58°F
- yearly average temperature, NOAA normal
- 83/100
- comfort score, above 81% of station-mapped location scores
- 39.9"
- yearly precipitation total
- 238 days
- growing season, frost-free days
Graton: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USC00043578 · Graton, CA 58°F mean · 39.9" 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 ≈ Napa County
- PRCP-MID 39.9"
- SWING-NARROW 20°F
- COMF-TOP 83/100
- LOAD-HEAT 2,927 HDD
- STN-1 USC00043578
- BOOK-FULL 6/6 fields
Nearest mean-temperature peer: Napa 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.
- Graton (this station) 58°F
- Hot Santa Rosa Sono…, CA 58°F
- Near Napa County, CA 58°F
- Near Petaluma, CA 58°F
- Cold Big Sur, CA 57°F
Climate Living Index · Graton
Graton: 85/100 · grade A
Graton publishes 5 of 6 Living Index dimensions (NOAA annual/seasonal normals · NOAA daily multivariate normals); 1 missing weight rescale to 100.
PlainClimate-derived for Graton, not an official NOAA rating. Rankings still use Comfort Score 83/100 (separate formula). Breakpoints and limits.
| Dimension | Station value | Score |
|---|---|---|
| Normal heat + freeze calendar | 0 calendar days | 100/100 · A |
| Snowfall burden | 0.0 inches/year | 90/100 · A |
| Frost-free season | 238 days/year | 84/100 · B |
| Precipitation balance | 39.9 in · 4.9 from 35 in | 82/100 · B |
| Annual temperature balance | 57.8°F · 9.7° from 67.5°F | 69/100 · C |
Graton · 2026-08-04 · NOAA NCEI Climate Normals · method · Comfort Score method.
Graton is a temperate Köppen climate: Csb
Coldest-month mean 47.2°F and warmest-month mean 67.1°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
- 67.1°F
- Coldest month
- 47.2°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 Graton sits across the climate record
Three NOAA fields for Graton'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
- 58th percentile wetness
- Neither arid nor torrential versus 6,352 station totals.
- Seasonal temperature swing
- Narrower than 97%
- Warmest-to-coldest month gap for Graton is compact versus 6,861 complete station-years.
How Graton compares across U.S. station-mapped locations
Graton's comfort score vs. all station-mapped locations
PlainClimate composite comfort index (1–100), NOAA 1991–2020 normals
83 Top 19% score exceeds 81% 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
Graton's measured station temperature trend
MethodologyAcross 87 complete annual observations from 1926 to 2025, GRATON warmed at a fitted rate of 0.15°C per decade. The line shows the fitted change relative to its first year, not raw year-to-year temperatures or a forecast.
- Graton primary station fitted change +0.15 °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) | 37°F (3°C) | 48°F (9°C) | 7.9" | 0.0" | 11.2 | 0.0 |
| February | 62°F (17°C) | 39°F (4°C) | 51°F (10°C) | 7.5" | 0.0" | 6.7 | 0.0 |
| March | 66°F (19°C) | 41°F (5°C) | 53°F (12°C) | 5.2" | 0.0" | 3.7 | 0.0 |
| April | 70°F (21°C) | 42°F (6°C) | 56°F (13°C) | 2.6" | 0.0" | 1.5 | 0.5 |
| May | 75°F (24°C) | 46°F (8°C) | 60°F (16°C) | 1.4" | 0.0" | 0.0 | 1.8 |
| June | 81°F (27°C) | 48°F (9°C) | 65°F (18°C) | 0.4" | 0.0" | 0.0 | 5.8 |
| July | 83°F (28°C) | 51°F (10°C) | 67°F (19°C) | 0.0" | 0.0" | 0.0 | 6.2 |
| August | 84°F (29°C) | 50°F (10°C) | 67°F (19°C) | 0.1" | 0.0" | 0.0 | 7.8 |
| September | 84°F (29°C) | 48°F (9°C) | 66°F (19°C) | 0.2" | 0.0" | 0.0 | 8.1 |
| October | 78°F (26°C) | 44°F (7°C) | 61°F (16°C) | 2.0" | 0.0" | 0.5 | 4.1 |
| November | 67°F (19°C) | 40°F (4°C) | 53°F (12°C) | 4.4" | 0.0" | 6.1 | 0.0 |
| December | 58°F (14°C) | 37°F (3°C) | 47°F (8°C) | 8.3" | 0.0" | 13.0 | 0.0 |
The year, day by day
The calendar barely moves in Graton: no date carries a normal high of 90°F or a normal low at freezing. The year runs between 37°F near December 19 and 85°F near August 28.
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 37°F around December 19.
Where the wet dates fall
The likeliest wet date is January 1, when 43% of years recorded at least a hundredth of an inch. The driest is July 16 at 2%. Summed across the calendar, that is about 78 wet dates a year.
The widest day
September 11 carries the biggest normal gap between afternoon and dawn, 36°F between the normal high and the normal low.
Look up any date
Any date's 1991–2020 normal for Graton.
Where Graton Stands Nationally
Daily temperature swings run wider than most of the country, peaking near 36°F between the normal high and low.
Graton 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
13.2 days with precipitation
11.8 days with precipitation
11.1 days with precipitation
7.3 days with precipitation
4.1 days with precipitation
1.5 days with precipitation
0.4 days with precipitation
0.8 days with precipitation
1.5 days with precipitation
4.2 days with precipitation
8.8 days with precipitation
13.2 days with precipitation
Graton'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 19.9°F seasonal spread.
- Wettest month
- December, 8.3"
- Driest month
- July, 0.0"
- Wettest three months
- December, January, February (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 Graton, it arrives in quantity
39.9" of precipitation falls across only about 78 wet days here, averaging 0.51 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 78 a year, 21% of all days
- Average depth per wet day
- 0.51 inches
- Most wet days
- January, about 13
- 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.
Graton'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 13
50% probability date
Last Spring Freeze
March 20
50% probability date
Growing Season
238 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
2,927
Higher = more heating needed
Cooling Degree Days
327
Higher = more cooling needed
Warmest Month
August
Coldest Month
December
Nationwide similar cities
Other rankable U.S. places outside CA closest to Graton 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).
- Clayton, GA 58°F · 0.0°F off
- Danbury, NC 58°F · 0.0°F off
- Gilbert, AR 58°F · 0.0°F off
- Kiowa, KS 58°F · 0.0°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (39.9" here), excluding temperature-peer places.
- Portland, IN 39.9" · 0.0" off
- Hamilton, MO 39.9" · 0.0" off
- Malone, NY 39.9" · 0.0" off
- Eureka, KS 40.0" · 0.0" off
Data-derived climate profile
How Graton's climate pattern fits together
heating led · moderate · low swing
Heating is the larger measured load in Graton, at 2,927 degree days versus 327 for cooling. Unlike a strongly continental record, however, its 19.9°F month-to-month range is compact; persistent cool-season demand matters more than a dramatic summer-to-winter reversal.
Graton's frost-free season lasts about 238 days, a middle-length window whose endpoints matter more than the annual average. It describes freeze probability, not year-specific planting conditions.
Temperature varies within a narrow 19.9°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.
Graton's 39.9 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 Graton'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 Graton, not an official NOAA class or a year-ahead forecast.
Questions about Graton's climate
How much rain does Graton get? ▼
How many days above 90°F does Graton get? ▼
How much energy does heating and cooling require in Graton? ▼
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from Graton's primary station: GRATON (USC00043578). 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 a census-designated place (GEOID 0630812), not an incorporated municipality. Match rule for Graton: 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 Graton 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.