Walla Walla, Washington climate: Normal weather by month, frost dates and records
Walla Walla's normal year runs from 30°F December nights to 90°F July afternoons, with 18.7 inches of precipitation and 7 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 12.4°C, December lows of −1°C, July highs of 32°C, 476 mm of precipitation a year.
- NOAA stationWalla Walla Regional Airport
- Station IDUSW00024160
- Location46.09°N 118.29°W
- Elevation1,166 ft (355 m)
- Population33,901
On October 14, the normal high in Walla Walla is 64°F and the normal low 45°F, and the chance of measurable rain or snow is 27%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Walla Walla.
- Jan 42° 31°
- Feb 47° 33°
- Mar 56° 38°
- Apr 63° 43°
- May 71° 49°
- Jun 79° 55°
- Jul 90° 62°
- Aug 89° 62°
- Sep 79° 54°
- Oct 63° 44°
- Nov 49° 36°
- Dec 41° 30°
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 Walla Walla each month?
July is the warmest month, with normal highs of 90°F; December the coldest, with normal lows of 30°F. The most precipitation falls in November (2.25 in), the least in August (0.40 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. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 42°F | 31°F | 36.3°F | 2.10 | 1.0 | 13 | <1 | 17 | 9 h |
| February | 47°F | 33°F | 39.7°F | 1.59 | 2.2 | 11 | <1 | 13 | 10 h 20 min |
| March | 56°F | 38°F | 46.8°F | 2.11 | 0.2 | 12 | <1 | 6 | 11 h 50 min |
| April | 63°F | 43°F | 52.5°F | 1.98 | 0.0 | 11 | <1 | 1 | 13 h 30 min |
| May | 71°F | 49°F | 60.4°F | 2.07 | 0.0 | 10 | 1 | <1 | 15 h |
| June | 79°F | 55°F | 67.0°F | 1.24 | 0.0 | 7 | 5 | <1 | 15 h 40 min |
| July | 90°F | 62°F | 76.3°F | 0.47 | 0.0 | 3 | 18 | <1 | 15 h 30 min |
| August | 89°F | 62°F | 75.2°F | 0.40 | 0.0 | 3 | 16 | <1 | 14 h 10 min |
| September | 79°F | 54°F | 66.2°F | 0.64 | 0.0 | 4 | 3 | <1 | 12 h 40 min |
| October | 63°F | 44°F | 53.7°F | 1.66 | 0.1 | 9 | <1 | 2 | 11 h |
| November | 49°F | 36°F | 42.4°F | 2.25 | 0.3 | 13 | <1 | 10 | 9 h 30 min |
| December | 41°F | 30°F | 35.6°F | 2.23 | 2.7 | 14 | <1 | 20 | 8 h 40 min |
| Year (annual) | 64°F | 45°F | 54.3°F | 18.74 | 6.5 | 109 | 42 | 70 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 5°C | −1°C | 2.4°C | 53 mm | 3 cm |
| February | 8°C | 0°C | 4.3°C | 40 mm | 6 cm |
| March | 13°C | 3°C | 8.2°C | 54 mm | 1 cm |
| April | 17°C | 6°C | 11.4°C | 50 mm | 0 cm |
| May | 22°C | 10°C | 15.8°C | 53 mm | 0 cm |
| June | 26°C | 13°C | 19.4°C | 31 mm | 0 cm |
| July | 32°C | 17°C | 24.6°C | 12 mm | 0 cm |
| August | 31°C | 17°C | 24.0°C | 10 mm | 0 cm |
| September | 26°C | 12°C | 19.0°C | 16 mm | 0 cm |
| October | 17°C | 7°C | 12.1°C | 42 mm | 0 cm |
| November | 10°C | 2°C | 5.8°C | 57 mm | 1 cm |
| December | 5°C | −1°C | 2.0°C | 57 mm | 7 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00024160; 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 Walla Walla?
Normal highs sit between 65°F and 85°F in May, June and September. Of those, September has the fewest days with rain (4).
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 USW00024160.
When is the last frost in Walla Walla?
In Walla Walla, the last spring frost (32°F) comes after March 27 in half of years and after April 22 in one year in ten; the first autumn frost comes before October 31 in half of years and before October 15 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 271 year in 10 after April 22; 9 in 10 after March 3
- First autumn frost, half of years before
- October 311 year in 10 before October 15; 9 in 10 before November 17
NOAA puts the median frost-free season at 219 days, and the season without a hard freeze (28°F) at 253 days.
A hard freeze (28°F) comes after March 4 in half of springs and before November 14 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Walla Walla in zone 7a in ZIP code 99362, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Walla Walla's NOAA station is in zone 7b: the coldest night of a typical year reaches 9°F (26 complete years); the map interpolates between stations and terrain, so the station and the ZIP area can differ by half a zone.
Frost dates for every NOAA station in Washington · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USW00024160; 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 Walla Walla?
In a normal year in Walla Walla, 42 days a year reach 90°F (8 of them 100°F or more), 70 nights fall to 32°F or colder and 109 days bring measurable precipitation.
- Days at 90°F or more
- 42a normal year
- Days at 100°F or more
- 8a normal year
- Nights at 32°F or colder
- 70a normal year
- Days that stay below freezing
- 20high of 32°F or less
- Days with 0.01 inch of precipitation
- 109a normal year
- Days with 1 inch of snow or more
- 4a normal year
The highest temperature in this station's record (since 1949) is 116°F, on June 29, 2021; the lowest is −24°F, on December 30, 1968.
The wettest calendar year on that record is 1981, with 26.68 in; the snowiest season is 1968–69, with 49.3 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USW00024160; records: ACIS (NOAA Regional Climate Centers), station USW00024160. Records use complete months only; a month missing more than three days is left out.
How humid and windy is Walla Walla, and how clear are its skies?
The summer (June-August) dew point averages 45°F. The muggiest month is June, with an average dew point of 47°F; the driest air comes in December (28°F). March is the windiest month (9.3 mph on average), and July has the most clear or nearly clear hours (89%).
| Month | Dew point | Humidity | Afternoon humidity | Wind | Clear or few clouds | Overcast |
|---|---|---|---|---|---|---|
| January | 31°F | 77% | 70% | 7.3 mph | – | – |
| February | 31°F | 68% | 54% | 8.2 mph | 47% | 37% |
| March | 35°F | 60% | 44% | 9.3 mph | 50% | 30% |
| April | 39°F | 55% | 37% | 9.0 mph | 58% | 23% |
| May | 46°F | 53% | 36% | 8.5 mph | 63% | 20% |
| June | 47°F | 42% | 25% | 8.5 mph | 78% | 8% |
| July | 45°F | 33% | 19% | 8.4 mph | 89% | 4% |
| August | 44°F | 39% | 24% | 7.9 mph | 83% | 6% |
| September | 41°F | 50% | 32% | 7.4 mph | 75% | 12% |
| October | 37°F | 69% | 55% | 7.1 mph | 57% | 29% |
| November | 30°F | 77% | 71% | 7.5 mph | – | – |
| December | 28°F | 80% | 76% | 7.0 mph | – | – |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00024160. Monthly averages of all hours; afternoon humidity at 3 p.m. local standard time; sky as the share of hours NOAA's observations rate clear or few clouds (a dash where NOAA publishes no sky value).
How sunny is Walla Walla?
Over a year 81% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Walla Walla, 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 much heating and cooling does Walla Walla need?
A normal year in Walla Walla brings 4,798 heating degree days, 11% fewer than the median U.S. place (5,373), and 936 cooling degree days, 3% more 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 3,267 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 890 | 0 |
| February | 708 | 0 |
| March | 564 | 0 |
| April | 376 | 2 |
| May | 182 | 37 |
| June | 54 | 116 |
| July | 3 | 352 |
| August | 5 | 320 |
| September | 68 | 104 |
| October | 358 | 6 |
| November | 678 | 0 |
| December | 911 | 0 |
| Year (annual) | 4,798 | 936 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00024160. 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 Walla Walla been warmer than normal lately?
2025 averaged 55.8°F, 1.5°F above the 1991-2020 normal of 54.3°F. 3 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 55.1°F | +0.8°F | 11.71 | – |
| 2022 | 52.5°F | −1.8°F | 21.58 | – |
| 2023 | 54.1°F | −0.2°F | 12.59 | – |
| 2024 | 54.4°F | +0.1°F | 15.14 | – |
| 2025 | 55.8°F | +1.5°F | 14.42 | – |
Over 140 complete years from 1872 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 USW00024160; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Walla Walla's climate compare?
Walla Walla is warmer than 94 of the other 95 places with their own NOAA record in Washington, and wetter than 39. Across the 7,247 U.S. stations with normals, its annual mean of 54.3°F is warmer than 58%.
In the Köppen classification computed from these normals, Walla Walla 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 Walla Walla 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.
- Prescott, WA364 people · 14 mi N
- Dixie, WA130 people · 7 mi NE
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 Walla Walla's climate
What is the coldest month in Walla Walla?
December, with a normal high of 41°F and a normal low of 30°F. The warmest is July (90°F by day, 62°F at night).
Does it snow in Walla Walla?
Yes: 7 inches in a normal year, falling on 7 days with 0.1 inch or more, the most in December (2.7 inches).
What is the rainiest month in Walla Walla?
November, with 2.25 in of precipitation in a normal year; the driest is August with 0.40 in.
What plant hardiness zone is Walla Walla in?
The USDA's 2023 map puts Walla Walla in zone 7a in ZIP code 99362, the nearest ZIP area. By the same method at Walla Walla's NOAA station, the coldest night of a typical year reaches 9°F (26 years, 1991-2020): zone 7b.
How late can frost come in Walla Walla?
In half of years the last 32°F night comes after March 27; in one year in ten it comes after April 22. Waiting until April 22 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Walla Walla in OctoberThis month day by day, its records and recent years
- Washington climateThe statewide normals and every place in the state
- Whitman Mission, WA9 miles from this station, 51.7°F a year
- Milton-Freewater, OR12 miles from this station, 55.5°F a year
- Dayton, WA21 miles from this station, 51.1°F a year
- Ice Harbor Dam, WA30 miles from this station, 54.0°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made