Updated October 2026
Whitman Mission National Historic Site Weather by Month
Whitman Mission National Historic Site is warmest in July, when the nearest NOAA climate station averages a high of 90°F and a low of 54°F, and coldest in December, with an average high of 41°F and an average low of 27°F. May is the wettest month, with about 1.8 inches of precipitation.
These figures are NOAA's 1991–2020 climate normals, the 30-year average for each calendar month, from the nearest long-record weather station, 0.2 miles from the park's reference point. A single station cannot describe a whole park: temperatures elsewhere in Whitman Mission National Historic Site can differ from these, particularly with elevation.
Warmest month
Jul
90°F avg high
Coldest month
Dec
27°F avg low
Wettest month
May
1.8 in avg
Longest days
Jun
15.5 h of daylight
Average weather at Whitman Mission by month
| Month | Avg high | Avg low | Precipitation | Daylight |
|---|---|---|---|---|
| January | 42°F | 27°F | 1.7 in | 8.8 h |
| February | 48°F | 28°F | 1.4 in | 10.1 h |
| March | 57°F | 32°F | 1.7 in | 11.6 h |
| April | 65°F | 37°F | 1.5 in | 13.3 h |
| May | 73°F | 44°F | 1.8 in | 14.8 h |
| June | 80°F | 49°F | 1.1 in | 15.5 h |
| July | 90°F | 54°F | 0.4 in | 15.2 h |
| August | 90°F | 52°F | 0.4 in | 14.0 h |
| September | 80°F | 44°F | 0.7 in | 12.3 h |
| October | 66°F | 36°F | 1.3 in | 10.7 h |
| November | 50°F | 31°F | 1.7 in | 9.2 h |
| December | 41°F | 27°F | 1.7 in | 8.5 h |
| Year total | 15.4 in |
NOAA 1991–2020 climate normals from station USC00459200, 0.2 miles from the park's reference point. Daylight is the monthly average, computed from the park's latitude. Each month links to how crowded Whitman Mission is at that time of year.
Whitman Mission weather by season
Winter: December to February
Average highs climb from 41°F in December to 48°F in February, with average lows near 27°F. The average low is at or below freezing in all three months. Together the three months average 4.8 inches of precipitation, about 31% of the yearly total. Daylight is at its shortest, about 8.5 hours in December.
Spring: March to May
Average highs climb from 57°F in March to 73°F in May, with average lows between 32°F and 44°F. The average low is at or below freezing in March. Together the three months average 5 inches of precipitation, about 32% of the yearly total and more than in any other season. Daylight lengthens from about 11.6 hours in March to 14.8 in May.
Summer: June to August
Average highs climb from 80°F in June to 90°F in August, with average lows between 49°F and 54°F. The average high is 90°F or hotter in July and August. Together the three months average 1.9 inches of precipitation, about 12% of the yearly total and less than in any other season. Daylight is at its longest, about 15.5 hours in June.
Fall: September to November
Average highs fall from 80°F in September to 50°F in November, with average lows between 31°F and 44°F. The average low is at or below freezing in November. Together the three months average 3.7 inches of precipitation, about 24% of the yearly total. Daylight shortens from about 12.3 hours in September to 9.2 in November.
What the National Park Service says about the weather
Summers are hot. Hats, water and sunblock are recommended. Winters are mild and rainy with a few snow storms. Layered clothing is advised.
Weather description courtesy of the National Park Service — official park site.
Today's forecast for Whitman Mission
Averages describe a typical month, not this week. For current conditions and the seven-day outlook, the National Weather Service issues a forecast for the park's reference point at 46.04°N, 118.46°W. It covers that one spot, so other elevations in the park can differ from it, as they do from the averages above.
National Weather Service forecast for Whitman Mission National Historic Site →
Weather and crowds together
July, the warmest month, sees about 1.3× the visitors of the park's average month. May is the busiest month of the year and December the quietest. To see those crowds set against the weather for all twelve months, read the best time to visit Whitman Mission National Historic Site. For hotels, cabins and rentals close to the park, see where to stay near Whitman Mission.
Where to stay near Whitman Mission
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Top-rated places to stay near Whitman Mission
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Frequently Asked Questions
July is the warmest month at Whitman Mission National Historic Site, with an average high of 90°F and an average low of 54°F. That is the 1991–2020 average at the nearest long-record NOAA station, 0.2 miles from the park's reference point. Temperatures inside the park can differ, particularly with elevation.
December is the coldest month at Whitman Mission National Historic Site, with an average low of 27°F and an average high of 41°F, based on NOAA 1991–2020 climate normals.
May is the wettest month, with about 1.8 inches of precipitation. July and August are the driest, at about 0.4 inches each. The station records about 15.4 inches of precipitation in an average year.
Daylight at Whitman Mission National Historic Site runs from about 8.5 hours a day in December to about 15.5 hours in June, computed from the park's latitude.
Weather at nearby parks
Keep exploring
Sources: NOAA NCEI U.S. Climate Normals 1991–2020 (station USC00459200), daylight computed from latitude, weather description from the National Park Service, crowd levels from National Park Service Visitor Use Statistics (1979–2025). Updated 2026-10-11. Lodging results are provided by Stay22; WhenToVisitParks may earn a commission from bookings, at no extra cost to you.