Richland, Washington climate: Normal weather by month, frost dates and records
Richland's normal year runs from 28°F December nights to 89°F July afternoons, with 7.3 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 12.0°C, December lows of −2°C, July highs of 32°C, 185 mm of precipitation a year.
- NOAA stationRichland
- Station IDUSC00457015
- Location46.31°N 119.26°W
- Elevation373 ft (114 m)
- Population64,372
On October 23, the normal high in Richland is 60°F and the normal low 39°F, and the chance of measurable rain or snow is 25%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Richland.
- Jan 41° 29°
- Feb 48° 30°
- Mar 57° 35°
- Apr 65° 41°
- May 74° 48°
- Jun 80° 54°
- Jul 89° 60°
- Aug 88° 59°
- Sep 79° 51°
- Oct 64° 42°
- Nov 49° 34°
- Dec 40° 28°
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 Richland each month?
July is the warmest month, with normal highs of 89°F; December the coldest, with normal lows of 28°F. The most precipitation falls in December (1.07 in), the least in August (0.13 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 | 41°F | 29°F | 34.7°F | 1.04 | 12 | <1 | 21 | 9 h |
| February | 48°F | 30°F | 38.8°F | 0.67 | 9 | <1 | 18 | 10 h 20 min |
| March | 57°F | 35°F | 46.1°F | 0.64 | 8 | <1 | 10 | 11 h 50 min |
| April | 65°F | 41°F | 53.0°F | 0.62 | 7 | <1 | 2 | 13 h 30 min |
| May | 74°F | 48°F | 61.1°F | 0.63 | 7 | 1 | <1 | 15 h |
| June | 80°F | 54°F | 67.3°F | 0.56 | 5 | 4 | <1 | 15 h 50 min |
| July | 89°F | 60°F | 74.7°F | 0.23 | 2 | 16 | <1 | 15 h 30 min |
| August | 88°F | 59°F | 73.6°F | 0.13 | 2 | 15 | <1 | 14 h 10 min |
| September | 79°F | 51°F | 65.2°F | 0.29 | 3 | 3 | <1 | 12 h 40 min |
| October | 64°F | 42°F | 53.0°F | 0.54 | 7 | <1 | 3 | 11 h |
| November | 49°F | 34°F | 41.3°F | 0.87 | 10 | <1 | 14 | 9 h 30 min |
| December | 40°F | 28°F | 34.1°F | 1.07 | 12 | <1 | 22 | 8 h 40 min |
| Year (annual) | 65°F | 43°F | 53.6°F | 7.29 | 84 | 39 | 91 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 5°C | −2°C | 1.5°C | 26 mm |
| February | 9°C | −1°C | 3.8°C | 17 mm |
| March | 14°C | 2°C | 7.8°C | 16 mm |
| April | 18°C | 5°C | 11.7°C | 16 mm |
| May | 23°C | 9°C | 16.2°C | 16 mm |
| June | 27°C | 12°C | 19.6°C | 14 mm |
| July | 32°C | 16°C | 23.7°C | 6 mm |
| August | 31°C | 15°C | 23.1°C | 3 mm |
| September | 26°C | 11°C | 18.4°C | 7 mm |
| October | 18°C | 5°C | 11.7°C | 14 mm |
| November | 9°C | 1°C | 5.2°C | 22 mm |
| December | 4°C | −2°C | 1.2°C | 27 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Ice Harbor Dam (19 miles away), gets 2 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00457015; 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 Richland?
Normal highs sit between 65°F and 85°F in April, May, June and September. Of those, September has the fewest days with rain (3).
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 USC00457015.
When is the last frost in Richland?
In Richland, the last spring frost (32°F) comes after April 6 in half of years and after April 24 in one year in ten; the first autumn frost comes before October 24 in half of years and before October 10 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 61 year in 10 after April 24; 9 in 10 after March 22
- First autumn frost, half of years before
- October 241 year in 10 before October 10; 9 in 10 before November 8
NOAA puts the median frost-free season at 200 days, and the season without a hard freeze (28°F) at 229 days.
A hard freeze (28°F) comes after March 18 in half of springs and before November 4 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Richland in zone 7b across its 2 ZIP code areas (7b in 99352, the largest). By the map's own method, the average of each year's coldest night over 1991-2020, Richland's NOAA station is in zone 7b: the coldest night of a typical year reaches 8°F (28 complete years).
Frost dates for every NOAA station in Washington · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00457015; 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 Richland ZIP code in?
The USDA's 2023 map gives each ZIP code area one zone. Richland's 2 ZIP code areas are all in zone 7b. 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 Richland?
In a normal year in Richland, 39 days a year reach 90°F (5 of them 100°F or more), 91 nights fall to 32°F or colder and 84 days bring measurable precipitation.
- Days at 90°F or more
- 39a normal year
- Days at 100°F or more
- 5a normal year
- Nights at 32°F or colder
- 91a normal year
- Days that stay below freezing
- 18high of 32°F or less
- Days with 0.01 inch of precipitation
- 84a normal year
The highest temperature in this station's record (since 1944) is 113°F, on July 30, 2020; the lowest is −22°F, on February 3, 1950.
The wettest calendar year on that record is 2010, with 10.02 in; the snowiest season is 1992–93, with 39.3 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00457015; records: ACIS (NOAA Regional Climate Centers), station USC00457015. Records use complete months only; a month missing more than three days is left out.
How sunny is Richland?
Over a year 81% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Richland, 4.2 kWh per square metre a day. July is the sunniest month (94%) and December the cloudiest (55%). Among the 459 U.S. places of 50,000 or more, that ranks tied 111th (with 13 others) in sunshine.
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 56% | 1.2 |
| February | 69% | 2.3 |
| March | 72% | 3.6 |
| April | 79% | 5.4 |
| May | 81% | 6.5 |
| June | 85% | 7.2 |
| July | 94% | 7.7 |
| August | 92% | 6.4 |
| September | 87% | 4.7 |
| October | 79% | 3.0 |
| November | 65% | 1.6 |
| December | 55% | 1.0 |
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 Richland need?
A normal year in Richland brings 4,935 heating degree days, 8% fewer than the median U.S. place (5,373), and 795 cooling degree days, 12% fewer than the median (908). Seven months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 3,125 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 939 | 0 |
| February | 734 | 0 |
| March | 586 | 0 |
| April | 360 | 2 |
| May | 155 | 34 |
| June | 40 | 109 |
| July | 3 | 302 |
| August | 5 | 270 |
| September | 70 | 75 |
| October | 376 | 4 |
| November | 711 | 0 |
| December | 956 | 0 |
| Year (annual) | 4,935 | 795 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00457015. 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 Richland been warmer than normal lately?
2025 averaged 55.7°F, 2.1°F above the 1991-2020 normal of 53.6°F. 4 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 55.6°F | +2.0°F | 5.34 |
| 2022 | 52.8°F | −0.9°F | 7.73 |
| 2023 | 54.4°F | +0.8°F | 6.98 |
| 2024 | 54.7°F | +1.1°F | 8.87 |
| 2025 | 55.7°F | +2.1°F | 9.41 |
Over 62 complete years from 1949 to 2025, the station's annual mean temperature rose at a fitted 2.3°F per century (+0.13°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00457015; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Richland's climate compare?
Richland is warmer than 89 of the other 95 places with their own NOAA record in Washington, and wetter than 0. Across the 7,247 U.S. stations with normals, its annual mean of 53.6°F is warmer than 55%.
In the Köppen classification computed from these normals, Richland is BWk: cold desert. 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 Richland share this climate record?
2 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.
- West Richland, WA18,820 people · 6 mi W
- Benton City, WA3,876 people · 11 mi W
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 Richland's climate
What is the coldest month in Richland?
December, with a normal high of 40°F and a normal low of 28°F. The warmest is July (89°F by day, 60°F at night).
Does it snow in Richland?
Yes. NOAA publishes no 1991-2020 snowfall normal for Richland's NOAA station; the nearest record that keeps one, Ice Harbor Dam (19 miles away), records 2 inches of snow in a normal year.
What is the rainiest month in Richland?
December, with 1.07 in of precipitation in a normal year; the driest is August with 0.13 in.
What plant hardiness zone is Richland in?
The USDA's 2023 map puts Richland in zone 7b across its 2 ZIP code areas (7b in 99352, the largest). By the same method at Richland's NOAA station, the coldest night of a typical year reaches 8°F (28 years, 1991-2020): zone 7b.
How late can frost come in Richland?
In half of years the last 32°F night comes after April 6; in one year in ten it comes after April 24. Waiting until April 24 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Richland in OctoberThis month day by day, its records and recent years
- Washington climateThe statewide normals and every place in the state
- Pasco, WA7 miles from this station, 53.3°F a year
- Eltopia (8 mi WSW), WA8 miles from this station, 51.9°F a year
- Kennewick, WA11 miles from this station, 55.0°F a year
- Sagemoor, WA11 miles from this station, 52.0°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made