Angwin, California climate: Normal weather by month, frost dates and records
Angwin's normal year runs from 39°F December nights to 85°F July afternoons, with 39.7 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 14.1°C, December lows of 4°C, July highs of 29°C, 1,009 mm of precipitation a year.
- NOAA stationAngwin Pacific Union College
- Station IDUSC00040212
- Location38.57°N 122.44°W
- Elevation1,715 ft (523 m)
- From the centerunder 1 mile
- Population (census place)2,774
On October 14, the normal high in Angwin is 73°F and the normal low 50°F, and the chance of measurable rain or snow is 12%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Angwin.
- Jan 54° 39°
- Feb 56° 40°
- Mar 60° 41°
- Apr 66° 42°
- May 73° 47°
- Jun 80° 51°
- Jul 85° 54°
- Aug 84° 54°
- Sep 81° 53°
- Oct 72° 50°
- Nov 60° 43°
- Dec 53° 39°
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 Angwin each month?
July is the warmest month, with normal highs of 85°F; December the coldest, with normal lows of 39°F. The most precipitation falls in December (8.30 in), the least in July (0.01 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 54°F | 39°F | 46.5°F | 7.80 | 13 | <1 | 4 | 9 h 40 min |
| February | 56°F | 40°F | 47.8°F | 7.59 | 12 | <1 | 3 | 10 h 40 min |
| March | 60°F | 41°F | 50.6°F | 5.50 | 11 | <1 | 2 | 11 h 50 min |
| April | 66°F | 42°F | 54.1°F | 2.37 | 8 | <1 | 1 | 13 h 10 min |
| May | 73°F | 47°F | 59.7°F | 1.56 | 5 | 1 | <1 | 14 h 10 min |
| June | 80°F | 51°F | 65.7°F | 0.36 | 1 | 4 | <1 | 14 h 50 min |
| July | 85°F | 54°F | 69.4°F | 0.01 | <1 | 8 | <1 | 14 h 40 min |
| August | 84°F | 54°F | 69.1°F | 0.04 | <1 | 8 | <1 | 13 h 40 min |
| September | 81°F | 53°F | 67.4°F | 0.17 | 1 | 5 | <1 | 12 h 30 min |
| October | 72°F | 50°F | 61.1°F | 1.92 | 4 | 1 | <1 | 11 h 20 min |
| November | 60°F | 43°F | 51.3°F | 4.09 | 9 | <1 | 1 | 10 h 10 min |
| December | 53°F | 39°F | 45.8°F | 8.30 | 14 | <1 | 4 | 9 h 30 min |
| Year (annual) | 69°F | 46°F | 57.4°F | 39.71 | 77 | 27 | 15 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 12°C | 4°C | 8.1°C | 198 mm |
| February | 13°C | 4°C | 8.8°C | 193 mm |
| March | 16°C | 5°C | 10.3°C | 140 mm |
| April | 19°C | 6°C | 12.3°C | 60 mm |
| May | 23°C | 8°C | 15.4°C | 40 mm |
| June | 27°C | 11°C | 18.7°C | 9 mm |
| July | 29°C | 12°C | 20.8°C | 0 mm |
| August | 29°C | 12°C | 20.6°C | 1 mm |
| September | 27°C | 12°C | 19.7°C | 4 mm |
| October | 22°C | 10°C | 16.2°C | 49 mm |
| November | 15°C | 6°C | 10.7°C | 104 mm |
| December | 12°C | 4°C | 7.7°C | 211 mm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00040212; 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 Angwin?
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 USC00040212.
When is the last frost in Angwin?
In Angwin, the last spring frost (32°F) comes after April 7 in half of years and after April 30 in one year in ten; the first autumn frost comes before December 5 in half of years and before November 14 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- April 71 year in 10 after April 30; 9 in 10 after February 23
- First autumn frost, half of years before
- December 51 year in 10 before November 14; 9 in 10 before January 1
NOAA puts the median frost-free season at 245 days, and the season without a hard freeze (28°F) at 321 days.
A hard freeze (28°F) comes after February 18 in half of springs and before December 30 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Angwin in zone 9b in ZIP code 94508. By the map's own method, the average of each year's coldest night over 1991-2020, Angwin's NOAA station is in zone 9b: the coldest night of a typical year reaches 27°F (26 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 USC00040212; 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.
How hot and how cold does it get in Angwin?
In a normal year in Angwin, 27 days a year reach 90°F (1 of them 100°F or more), 15 nights fall to 32°F or colder and 77 days bring measurable precipitation.
- Days at 90°F or more
- 27a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 15a normal year
- Days that stay below freezing
- fewer than 1high of 32°F or less
- Days with 0.01 inch of precipitation
- 77a normal year
The highest temperature in this station's record (since 1952) is 110°F, on July 15, 1972; the lowest is 14°F, on December 9, 1972.
The wettest calendar year on that record is 1973, with 62.23 in; the snowiest season is 1951–52, with 23.3 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00040212; records: ACIS (NOAA Regional Climate Centers), station USC00040212. Records use complete months only; a month missing more than three days is left out.
How sunny is Angwin?
Over a year 87% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Angwin, 5.1 kWh per square metre a day. July is the sunniest month (95%) and December the cloudiest (72%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 74% | 2.3 |
| February | 77% | 3.3 |
| March | 78% | 4.6 |
| April | 84% | 6.1 |
| May | 88% | 7.3 |
| June | 93% | 8.1 |
| July | 95% | 8.0 |
| August | 94% | 7.1 |
| September | 93% | 5.8 |
| October | 88% | 4.2 |
| November | 81% | 2.8 |
| December | 72% | 2.0 |
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 Angwin need?
A normal year in Angwin brings 3,375 heating degree days, 37% fewer than the median U.S. place (5,373), and 604 cooling degree days, 33% fewer than the median (908). Six months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 3,278 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 574 | 0 |
| February | 482 | 0 |
| March | 448 | 2 |
| April | 334 | 7 |
| May | 200 | 36 |
| June | 74 | 94 |
| July | 20 | 155 |
| August | 21 | 148 |
| September | 46 | 117 |
| October | 168 | 45 |
| November | 413 | 2 |
| December | 597 | 0 |
| Year (annual) | 3,375 | 604 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00040212. 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 Angwin been warmer than normal lately?
2025 averaged 56.8°F, 0.6°F below the 1991-2020 normal of 57.4°F. 3 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 58.0°F | +0.6°F | 35.65 |
| 2022 | 58.5°F | +1.1°F | 23.77 |
| 2023 | 56.2°F | −1.2°F | 48.36 |
| 2024 | 58.4°F | +1.0°F | 54.52 |
| 2025 | 56.8°F | −0.6°F | 36.11 |
Over 49 complete years from 1953 to 2025, the station's annual mean temperature rose at a fitted 2.9°F per century (+0.16°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00040212; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Angwin's climate compare?
Angwin is warmer than 53 of the other 218 places with their own NOAA record in California, and wetter than 185. Across the 7,247 U.S. stations with normals, its annual mean of 57.4°F is warmer than 68%.
In the Köppen classification computed from these normals, Angwin 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.
Questions about Angwin's climate
What is the coldest month in Angwin?
December, with a normal high of 53°F and a normal low of 39°F. The warmest is July (85°F by day, 54°F at night).
What is the rainiest month in Angwin?
December, with 8.30 in of precipitation in a normal year; the driest is July with 0.01 in.
What plant hardiness zone is Angwin in?
The USDA's 2023 map puts Angwin in zone 9b in ZIP code 94508. By the same method at Angwin's NOAA station, the coldest night of a typical year reaches 27°F (26 years, 1991-2020): zone 9b.
How late can frost come in Angwin?
In half of years the last 32°F night comes after April 7; in one year in ten it comes after April 30. Waiting until April 30 leaves about a one-in-ten chance of a later frost.
Nearby and next
- California climateThe statewide normals and every place in the state
- St. Helena, CA5 miles from this station, 61.0°F a year
- Calistoga, CA9 miles from this station, 60.1°F a year
- Markley Cove, CA18 miles from this station, 60.7°F a year
- Sonoma, CA19 miles from this station, 59.0°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made