San Rafael, California climate: Normal weather by month, frost dates and records
San Rafael's normal year runs from 42°F December nights to 81°F August afternoons, with 34.5 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 15.3°C, December lows of 6°C, August highs of 27°C, 875 mm of precipitation a year.
- NOAA stationSan Rafael Civic Center
- Station IDUSC00047880
- Location38.00°N 122.54°W
- Elevation120 ft (37 m)
- From the center2 miles
- Population59,961
On October 14, the normal high in San Rafael is 76°F and the normal low 52°F, and the chance of measurable rain or snow is 11%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for San Rafael.
- Jan 57° 43°
- Feb 61° 44°
- Mar 65° 46°
- Apr 68° 48°
- May 72° 51°
- Jun 78° 54°
- Jul 81° 55°
- Aug 81° 56°
- Sep 81° 54°
- Oct 75° 51°
- Nov 65° 46°
- Dec 57° 42°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in San Rafael each month?
August is the warmest month, with normal highs of 81°F; December the coldest, with normal lows of 42°F. The most precipitation falls in December (7.81 in), the least in July (0.00 in).
Each month has its own page with the day-by-day normals, the month's records and its recent years:
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 57°F | 43°F | 49.8°F | 7.13 | 13 | <1 | 1 | 9 h 50 min |
| February | 61°F | 44°F | 52.5°F | 6.94 | 11 | <1 | <1 | 10 h 50 min |
| March | 65°F | 46°F | 55.2°F | 4.42 | 10 | <1 | <1 | 11 h 50 min |
| April | 68°F | 48°F | 57.7°F | 1.99 | 6 | <1 | <1 | 13 h 10 min |
| May | 72°F | 51°F | 61.3°F | 0.94 | 3 | 1 | <1 | 14 h 10 min |
| June | 78°F | 54°F | 65.7°F | 0.15 | 1 | 4 | <1 | 14 h 50 min |
| July | 81°F | 55°F | 67.9°F | 0.00 | <1 | 4 | <1 | 14 h 30 min |
| August | 81°F | 56°F | 68.4°F | 0.05 | <1 | 4 | <1 | 13 h 40 min |
| September | 81°F | 54°F | 67.6°F | 0.07 | 1 | 5 | <1 | 12 h 30 min |
| October | 75°F | 51°F | 63.2°F | 1.46 | 4 | 1 | <1 | 11 h 20 min |
| November | 65°F | 46°F | 55.3°F | 3.49 | 7 | <1 | <1 | 10 h 10 min |
| December | 57°F | 42°F | 49.6°F | 7.81 | 12 | <1 | 1 | 9 h 30 min |
| Year (annual) | 70°F | 49°F | 59.5°F | 34.45 | 69 | 20 | 3 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 14°C | 6°C | 9.9°C | 181 mm |
| February | 16°C | 7°C | 11.4°C | 176 mm |
| March | 18°C | 8°C | 12.9°C | 112 mm |
| April | 20°C | 9°C | 14.3°C | 51 mm |
| May | 22°C | 10°C | 16.3°C | 24 mm |
| June | 26°C | 12°C | 18.7°C | 4 mm |
| July | 27°C | 13°C | 19.9°C | 0 mm |
| August | 27°C | 13°C | 20.2°C | 1 mm |
| September | 27°C | 12°C | 19.8°C | 2 mm |
| October | 24°C | 11°C | 17.3°C | 37 mm |
| November | 18°C | 8°C | 12.9°C | 89 mm |
| December | 14°C | 6°C | 9.8°C | 198 mm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00047880; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit San Rafael?
Normal highs sit between 65°F and 85°F in April, May, June, July, August, September and October. Of those, July has the fewest days with rain (0).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00047880.
When is the last frost in San Rafael?
In San Rafael, the last spring frost (32°F) comes after January 11 in half of years and after February 25 in one year in ten; the first autumn frost comes before December 21 in half of years and before December 2 in one year in ten. A night at 32°F or colder comes at all in 70% of years here (NOAA).
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- January 111 year in 10 after February 25; 9 in 10 after December 14
- First autumn frost, half of years before
- December 211 year in 10 before December 2; 9 in 10 before February 9
NOAA puts the median frost-free season at 349 days, and the season without a hard freeze (28°F) at 365 days.
A hard freeze (28°F) comes after December 31 in half of springs and before December 29 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts San Rafael in zones 9b to 10a across its 2 ZIP code areas (10a in 94901, the largest). By the map's own method, the average of each year's coldest night over 1991-2020, San Rafael's NOAA station is in zone 10a: the coldest night of a typical year reaches 31°F (18 complete years).
Frost dates for every NOAA station in California · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00047880; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
What hardiness zone is each San Rafael ZIP code in?
The USDA's 2023 map gives each ZIP code area one zone. San Rafael's 2 ZIP code areas run from zone 9b to 10a: 1 in 10a and 1 in 9b. Each ZIP's frost dates are in the frost tool.
Source: USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; ZIP areas in the place: Census Bureau 2020 ZCTA-to-place relationship file. A ZIP area counts when at least a tenth of its land (and 0.5 km²) lies in the place.
How hot and how cold does it get in San Rafael?
In a normal year in San Rafael, 20 days a year reach 90°F (1 of them 100°F or more), 3 nights fall to 32°F or colder and 69 days bring measurable precipitation.
- Days at 90°F or more
- 20a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 3a normal year
- Days that stay below freezing
- fewer than 1high of 32°F or less
- Days with 0.01 inch of precipitation
- 69a normal year
The highest temperature in this station's record (since 1894) is 110°F, on June 15, 1961; the lowest is 20°F, on December 22, 1990.
The wettest calendar year on that record is 1995, with 59.67 in.
Source: NOAA NCEI 1991-2020 annual normals, station USC00047880; records: ACIS (NOAA Regional Climate Centers), station USC00047880. Records use complete months only; a month missing more than three days is left out.
How sunny is San Rafael?
Over a year 80% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around San Rafael, 4.7 kWh per square metre a day. June is the sunniest month (84%) and December the cloudiest (74%). Among the 459 U.S. places of 50,000 or more, that ranks tied 125th (with 50 others) in sunshine.
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 76% | 2.5 |
| February | 77% | 3.4 |
| March | 79% | 4.6 |
| April | 82% | 6.0 |
| May | 81% | 6.7 |
| June | 84% | 7.3 |
| July | 78% | 6.5 |
| August | 77% | 5.8 |
| September | 82% | 5.1 |
| October | 83% | 4.0 |
| November | 81% | 2.8 |
| December | 74% | 2.1 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does San Rafael need?
A normal year in San Rafael brings 2,481 heating degree days, 54% fewer than the median U.S. place (5,373), and 486 cooling degree days, 46% fewer than the median (908). Four months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 3,652 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 473 | 0 |
| February | 349 | 0 |
| March | 306 | 1 |
| April | 228 | 8 |
| May | 146 | 31 |
| June | 54 | 75 |
| July | 19 | 109 |
| August | 14 | 119 |
| September | 25 | 101 |
| October | 98 | 40 |
| November | 293 | 2 |
| December | 477 | 0 |
| Year (annual) | 2,481 | 486 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00047880. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
Has San Rafael been warmer than normal lately?
2024 averaged 61.6°F, 2.1°F above the 1991-2020 normal of 59.5°F. 2 of the 2 complete years since 2023 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2023 | 60.3°F | +0.8°F | 38.17 |
| 2024 | 61.6°F | +2.1°F | 40.96 |
Over 31 complete years from 1952 to 2024, the station's annual mean temperature rose at a fitted 3.3°F per century (+0.18°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00047880; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does San Rafael's climate compare?
San Rafael is warmer than 84 of the other 218 places with their own NOAA record in California, and wetter than 176. Across the 7,247 U.S. stations with normals, its annual mean of 59.5°F is warmer than 73%.
In the Köppen classification computed from these normals, San Rafael is Csb: temperate, dry-summer, warm summer. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Which places near San Rafael share this climate record?
12 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Novato, CAalso near: Kentfield (9 mi, 59.2°F a year); Petaluma (12 mi, 58.0°F a year)52,311 people · 6 mi N
- San Anselmo, CA12,645 people · 2 mi SW
- Fairfax, CA7,476 people · 3 mi W
- Lucas Valley-Marinwood, CA6,331 people · 4 mi NW
- Santa Venetia, CA3,937 people · 2 mi E
- Sleepy Hollow, CA2,644 people · 3 mi W
- Lagunitas-Forest Knolls, CA1,795 people · 9 mi W
- Woodacre, CA1,574 people · 6 mi W
- Black Point-Green Point, CA1,560 people · 8 mi N
- San Geronimo, CA562 people · 7 mi W
- Point Reyes Station, CA465 people · 16 mi W
- Nicasio, CA113 people · 10 mi NW
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about San Rafael's climate
What is the coldest month in San Rafael?
December, with a normal high of 57°F and a normal low of 42°F. The warmest is August (81°F by day, 56°F at night).
Does it snow in San Rafael?
Rarely: NOAA's normal is no measurable snow a year.
What is the rainiest month in San Rafael?
December, with 7.81 in of precipitation in a normal year; the driest is July with 0.00 in.
What plant hardiness zone is San Rafael in?
The USDA's 2023 map puts San Rafael in zones 9b to 10a across its 2 ZIP code areas (10a in 94901, the largest). By the same method at San Rafael's NOAA station, the coldest night of a typical year reaches 31°F (18 years, 1991-2020): zone 10a.
How late can frost come in San Rafael?
In half of years the last 32°F night comes after January 11; in one year in ten it comes after February 25. Waiting until February 25 leaves about a one-in-ten chance of a later frost.
Nearby and next
- San Rafael in OctoberThis month day by day, its records and recent years
- California climateThe statewide normals and every place in the state
- Kentfield, CA3 miles from this station, 59.2°F a year
- Richmond, CA11 miles from this station, 58.8°F a year
- San Francisco, CA17 miles from this station, 57.7°F a year
- Berkeley, CA17 miles from this station, 58.5°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made