Richardson Grove State Park, California climate: Climate normals at a NOAA weather station
Richardson Grove State Park's normal year runs from 38°F December nights to 87°F August afternoons, with 65.4 inches of precipitation and less than an inch of snow (0.2 in) a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 13.4°C, December lows of 4°C, August highs of 30°C, 1,662 mm of precipitation a year.
- NOAA stationRichardson Grove State Park
- Station IDUSC00047404
- Location40.03°N 123.79°W
- Elevation503 ft (153 m)
On October 23, the normal high in Richardson Grove State Park is 65°F and the normal low 44°F, and the chance of measurable rain or snow is 19%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Richardson Grove State Park.
- Jan 50° 39°
- Feb 53° 40°
- Mar 59° 41°
- Apr 64° 42°
- May 72° 47°
- Jun 77° 51°
- Jul 86° 54°
- Aug 87° 54°
- Sep 83° 50°
- Oct 70° 45°
- Nov 55° 41°
- Dec 49° 38°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like at Richardson Grove State Park each month?
August is the warmest month, with normal highs of 87°F; December the coldest, with normal lows of 38°F. The most precipitation falls in December (14.03 in), the least in July (0.01 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 50°F | 39°F | 44.4°F | 12.73 | 17 | <1 | 5 | 9 h 40 min |
| February | 53°F | 40°F | 46.1°F | 11.32 | 14 | <1 | 3 | 10 h 40 min |
| March | 59°F | 41°F | 49.6°F | 9.71 | 12 | <1 | 2 | 11 h 50 min |
| April | 64°F | 42°F | 53.3°F | 5.09 | 9 | <1 | 1 | 13 h 10 min |
| May | 72°F | 47°F | 59.4°F | 1.92 | 6 | 1 | 1 | 14 h 20 min |
| June | 77°F | 51°F | 64.1°F | 0.78 | 2 | 2 | <1 | 15 h |
| July | 86°F | 54°F | 69.9°F | 0.01 | <1 | 10 | <1 | 14 h 50 min |
| August | 87°F | 54°F | 70.3°F | 0.04 | <1 | 9 | <1 | 13 h 50 min |
| September | 83°F | 50°F | 66.5°F | 0.41 | 1 | 7 | <1 | 12 h 30 min |
| October | 70°F | 45°F | 57.4°F | 2.74 | 4 | 1 | <1 | 11 h 10 min |
| November | 55°F | 41°F | 48.2°F | 6.66 | 12 | <1 | 3 | 10 h |
| December | 49°F | 38°F | 43.7°F | 14.03 | 15 | <1 | 6 | 9 h 20 min |
| Year (annual) | 67°F | 45°F | 56.1°F | 65.44 | 92 | 30 | 22 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 10°C | 4°C | 6.9°C | 323 mm |
| February | 11°C | 4°C | 7.8°C | 288 mm |
| March | 15°C | 5°C | 9.8°C | 247 mm |
| April | 18°C | 6°C | 11.8°C | 129 mm |
| May | 22°C | 8°C | 15.2°C | 49 mm |
| June | 25°C | 11°C | 17.8°C | 20 mm |
| July | 30°C | 12°C | 21.1°C | 0 mm |
| August | 30°C | 12°C | 21.3°C | 1 mm |
| September | 28°C | 10°C | 19.2°C | 10 mm |
| October | 21°C | 7°C | 14.1°C | 70 mm |
| November | 13°C | 5°C | 9.0°C | 169 mm |
| December | 9°C | 4°C | 6.5°C | 356 mm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00047404; 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.
Which months are mildest at Richardson Grove State Park?
Normal highs sit between 65°F and 85°F in May, June, September and October. Of those, September has the fewest days with rain (1).
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 USC00047404.
When is the last frost at Richardson Grove State Park?
In Richardson Grove State Park, the last spring frost (32°F) comes after March 10 in half of years and after April 13 in one year in ten; the first autumn frost comes before December 1 in half of years and before November 7 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
- March 101 year in 10 after April 13; 9 in 10 after January 9
- First autumn frost, half of years before
- December 11 year in 10 before November 7; 9 in 10 before January 9
NOAA puts the median frost-free season at 271 days, and the season without a hard freeze (28°F) at 351 days.
A hard freeze (28°F) comes after January 15 in half of springs and before December 26 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Richardson Grove State Park in zone 9a in ZIP code 95587, the nearest ZIP area.
Frost dates for every NOAA station in California · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00047404; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026. 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 at Richardson Grove State Park?
In a normal year in Richardson Grove State Park, 30 days a year reach 90°F (3 of them 100°F or more), 22 nights fall to 32°F or colder and 92 days bring measurable precipitation.
- Days at 90°F or more
- 30a normal year
- Days at 100°F or more
- 3a normal year
- Nights at 32°F or colder
- 22a normal year
- Days that stay below freezing
- fewer than 1high of 32°F or less
- Days with 0.01 inch of precipitation
- 92a normal year
The highest temperature in this station's record (since 1961) is 112°F, on July 16, 1972; the lowest is 15°F, on December 22, 1990.
The wettest calendar year on that record is 1983, with 127.89 in; the snowiest season is 1998–99, with 3.8 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00047404; records: ACIS (NOAA Regional Climate Centers), station USC00047404. Records use complete months only; a month missing more than three days is left out.
How sunny is it at Richardson Grove State Park?
Over a year 83% of the sunlight that would reach the ground under clear skies gets through the clouds at Richardson Grove State Park, 4.9 kWh per square metre a day. July is the sunniest month (95%) and December the cloudiest (63%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 68% | 2.0 |
| February | 70% | 2.9 |
| March | 70% | 4.1 |
| April | 76% | 5.5 |
| May | 82% | 6.9 |
| June | 89% | 7.9 |
| July | 95% | 8.1 |
| August | 95% | 7.2 |
| September | 92% | 5.7 |
| October | 85% | 3.9 |
| November | 73% | 2.4 |
| December | 63% | 1.6 |
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 many heating and cooling degree days does Richardson Grove State Park record?
A normal year at Richardson Grove State Park brings 3,734 heating degree days, 31% fewer than the median U.S. place (5,373), and 494 cooling degree days, 46% 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 2,942 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 637 | 0 |
| February | 528 | 0 |
| March | 477 | 0 |
| April | 354 | 1 |
| May | 195 | 20 |
| June | 76 | 49 |
| July | 9 | 160 |
| August | 7 | 171 |
| September | 41 | 86 |
| October | 243 | 7 |
| November | 506 | 0 |
| December | 662 | 0 |
| Year (annual) | 3,734 | 494 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00047404. 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.
How does Richardson Grove State Park's climate compare?
Richardson Grove State Park is warmer than 46 of the 219 places with their own NOAA record in California, and wetter than 212. Across the 7,247 U.S. stations with normals, its annual mean of 56.1°F is warmer than 64%.
In the Köppen classification computed from these normals, Richardson Grove State Park 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 Richardson Grove State Park share this climate record?
8 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.
- Garberville, CA1,568 people · 5 mi N
- Redway, CA1,276 people · 7 mi N
- Benbow, CA401 people · 3 mi NE
- Miranda, CA380 people · 14 mi N
- Ruth, CA165 people · 30 mi NE
- Alderpoint, CA62 people · 13 mi NE
- Leggett, CA44 people · 12 mi S
- Phillipsville, CA0 people · 13 mi N
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 Richardson Grove State Park's climate
What is the coldest month at Richardson Grove State Park?
December, with a normal high of 49°F and a normal low of 38°F. The warmest is August (87°F by day, 54°F at night).
Does it snow at Richardson Grove State Park?
Rarely: NOAA's normal is 0.2 inch a year.
What is the rainiest month at Richardson Grove State Park?
December, with 14.03 in of precipitation in a normal year; the driest is July with 0.01 in.
What plant hardiness zone is Richardson Grove State Park in?
The USDA's 2023 map puts Richardson Grove State Park in zone 9a in ZIP code 95587, the nearest ZIP area.
How late can frost come at Richardson Grove State Park?
In half of years the last 32°F night comes after March 10; in one year in ten it comes after April 13. Waiting until April 13 leaves about a one-in-ten chance of a later frost.
Nearby and next
- California climateThe statewide normals and every place in the state
- Shelter Cove, CA15 miles from this station, 56.9°F a year
- Grizzly Creek State Park, CA32 miles from this station, 52.9°F a year
- Covelo, CA32 miles from this station, 55.8°F a year
- Scotia, CA35 miles from this station, 55.6°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made