Whitman Mission, Washington climate: Climate normals at a NOAA weather station
Whitman Mission's normal year runs from 27°F December nights to 90°F July afternoons, with 15.4 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 10.9°C, December lows of −3°C, July highs of 32°C, 391 mm of precipitation a year.
- NOAA stationWhitman Mission
- Station IDUSC00459200
- Location46.04°N 118.46°W
- Elevation632 ft (193 m)
On October 23, the normal high in Whitman Mission is 62°F and the normal low 34°F.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Whitman Mission.
- Jan 42° 27°
- Feb 48° 28°
- Mar 57° 32°
- Apr 65° 37°
- May 73° 44°
- Jun 80° 49°
- Jul 90° 54°
- Aug 90° 52°
- Sep 80° 44°
- Oct 66° 36°
- Nov 50° 31°
- Dec 41° 27°
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 Whitman Mission each month?
July is the warmest month, with normal highs of 90°F; December the coldest, with normal lows of 27°F. The most precipitation falls in May (1.80 in), the least in July (0.38 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 42°F | 27°F | 34.8°F | 1.68 | – | <1 | 23 | 9 h |
| February | 48°F | 28°F | 37.9°F | 1.38 | – | <1 | 20 | 10 h 20 min |
| March | 57°F | 32°F | 44.7°F | 1.70 | – | <1 | 16 | 11 h 50 min |
| April | 65°F | 37°F | 50.7°F | 1.53 | – | <1 | 8 | 13 h 30 min |
| May | 73°F | 44°F | 58.4°F | 1.80 | – | 1 | 2 | 15 h |
| June | 80°F | 49°F | 64.6°F | 1.14 | – | 4 | <1 | 15 h 40 min |
| July | 90°F | 54°F | 72.0°F | 0.38 | – | 17 | <1 | 15 h 30 min |
| August | 90°F | 52°F | 70.7°F | 0.40 | – | 17 | <1 | 14 h 10 min |
| September | 80°F | 44°F | 61.9°F | 0.68 | – | 4 | 1 | 12 h 40 min |
| October | 66°F | 36°F | 50.5°F | 1.30 | – | <1 | 13 | 11 h |
| November | 50°F | 31°F | 40.6°F | 1.67 | – | <1 | 18 | 9 h 30 min |
| December | 41°F | 27°F | 34.1°F | 1.73 | – | <1 | 24 | 8 h 40 min |
| Year (annual) | 65°F | 38°F | 51.7°F | 15.39 | – | 44 | 125 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 6°C | −3°C | 1.6°C | 43 mm |
| February | 9°C | −2°C | 3.3°C | 35 mm |
| March | 14°C | 0°C | 7.1°C | 43 mm |
| April | 18°C | 3°C | 10.4°C | 39 mm |
| May | 23°C | 7°C | 14.7°C | 46 mm |
| June | 27°C | 10°C | 18.1°C | 29 mm |
| July | 32°C | 12°C | 22.2°C | 10 mm |
| August | 32°C | 11°C | 21.5°C | 10 mm |
| September | 27°C | 7°C | 16.6°C | 17 mm |
| October | 19°C | 2°C | 10.3°C | 33 mm |
| November | 10°C | −1°C | 4.8°C | 42 mm |
| December | 5°C | −3°C | 1.2°C | 44 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Milton-Freewater (7 miles away), gets 7 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00459200; 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 Whitman Mission?
Normal highs sit between 65°F and 85°F in May, June, September and October.
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 USC00459200.
When is the last frost at Whitman Mission?
In Whitman Mission, the last spring frost (32°F) comes after May 2 in half of years and after May 18 in one year in ten; the first autumn frost comes before October 1 in half of years and before September 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
- May 21 year in 10 after May 18; 9 in 10 after April 16
- First autumn frost, half of years before
- October 11 year in 10 before September 14; 9 in 10 before October 16
NOAA puts the median frost-free season at 151 days, and the season without a hard freeze (28°F) at 181 days.
A hard freeze (28°F) comes after April 15 in half of springs and before October 12 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Whitman Mission in zone 7a in ZIP code 99324, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, the station is in zone 7a: the coldest night of a typical year reaches 3°F (15 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 USC00459200; 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 at Whitman Mission?
In a normal year in Whitman Mission, 44 days a year reach 90°F (8 of them 100°F or more) and 125 nights fall to 32°F or colder.
- Days at 90°F or more
- 44a normal year
- Days at 100°F or more
- 8a normal year
- Nights at 32°F or colder
- 125a normal year
- Days that stay below freezing
- 20high of 32°F or less
The highest temperature in this station's record (since 1962) is 114°F, on June 30, 2021; the lowest is −27°F, on December 31, 1968.
The wettest calendar year on that record is 2010, with 17.59 in; the snowiest season is 2008–09, with 29.8 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00459200; records: ACIS (NOAA Regional Climate Centers), station USC00459200. Records use complete months only; a month missing more than three days is left out.
How sunny is it at Whitman Mission?
Over a year 81% of the sunlight that would reach the ground under clear skies gets through the clouds at Whitman Mission, 4.2 kWh per square metre a day. July is the sunniest month (94%) and December the cloudiest (55%).
| 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 many heating and cooling degree days does Whitman Mission record?
A normal year at Whitman Mission brings 5,357 heating degree days, 0% fewer than the median U.S. place (5,373), and 554 cooling degree days, 39% 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 2,616 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 936 | 0 |
| February | 757 | 0 |
| March | 629 | 0 |
| April | 430 | 1 |
| May | 223 | 20 |
| June | 80 | 70 |
| July | 12 | 229 |
| August | 19 | 195 |
| September | 130 | 39 |
| October | 449 | 1 |
| November | 732 | 0 |
| December | 959 | 0 |
| Year (annual) | 5,357 | 554 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00459200. 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.
Have recent years at Whitman Mission been warmer than normal?
2021 averaged 53.0°F, 1.3°F above the 1991-2020 normal of 51.7°F.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 53.0°F | +1.3°F | – |
Over 44 complete years from 1963 to 2024, the station's annual mean temperature rose at a fitted 0.4°F per century (+0.02°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00459200; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Whitman Mission's climate compare?
Whitman Mission is warmer than 75 of the 96 places with their own NOAA record in Washington, and wetter than 30. Across the 7,247 U.S. stations with normals, its annual mean of 51.7°F is warmer than 48%.
In the Köppen classification computed from these normals, Whitman Mission is Csa: temperate, dry-summer, hot 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 Whitman Mission share this climate record?
5 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.
- Athena, OR1,184 people · 16 mi S
- Umapine, OR713 people · 5 mi S
- Weston, OR705 people · 16 mi S
- Adams, OR389 people · 20 mi S
- Helix, OR192 people · 16 mi SW
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 Whitman Mission's climate
What is the coldest month at Whitman Mission?
December, with a normal high of 41°F and a normal low of 27°F. The warmest is July (90°F by day, 54°F at night).
Does it snow at Whitman Mission?
Yes. NOAA publishes no 1991-2020 snowfall normal for the station; the nearest record that keeps one, Milton-Freewater (7 miles away), records 7 inches of snow in a normal year.
What is the rainiest month at Whitman Mission?
May, with 1.80 in of precipitation in a normal year; the driest is July with 0.38 in.
What plant hardiness zone is Whitman Mission in?
The USDA's 2023 map puts Whitman Mission in zone 7a in ZIP code 99324, the nearest ZIP area. By the same method at the station, the coldest night of a typical year reaches 3°F (15 years, 1991-2020): zone 7a.
How late can frost come at Whitman Mission?
In half of years the last 32°F night comes after May 2; in one year in ten it comes after May 18. Waiting until May 18 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Washington climateThe statewide normals and every place in the state
- Milton-Freewater, OR7 miles from this station, 55.5°F a year
- Walla Walla, WA9 miles from this station, 54.3°F a year
- Ice Harbor Dam, WA24 miles from this station, 54.0°F a year
- Dayton, WA29 miles from this station, 51.1°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made