Onalaska, WA
Full City Profile · Washington · Lewis County County
2.4
/5.0
C
Fair
657
Population
411/sq mi density
$412,800
Home Value
$508,905 Zillow
$910
Median Rent
24.4% income on rent
52°F
Avg Temperature
C
Overall
2.4 / 5.0
Fair overall score based on economy, affordability, safety and education
C
Education
2.4 / 5.0
18.0% bachelor's degree or higher
Onalaska experiences four distinct seasons with an average annual temperature of 52°F (11°C). Winters average 41°F in January while summers reach 66°F in July. Annual precipitation totals 58.7 inches. The area receives 3.4 inches of snow annually. Air quality is rated Good with a median AQI of 22.
Temperature
41°F Jan (5°C)
66°F Jul (19°C)
| Annual Average | 52.3°F |
| 3% below US avg | |
| January Average | 41°F (5°C) |
| July Average | 66°F (19°C) |
Geography
| Elevation | 501 ft (153 m) |
| Area | 1.6 sq mi (4.1 km²) |
| Population Density | 411/sq mi |
| Coordinates | 46.5782°N, 122.7111°W |
| Timezone | America/Los_Angeles |
| County | Lewis County County |
| Nearest Airport | Olympia Regional (OLM) 29 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 22.0 |
| Rating | Good |
| Good Days % | 93.3% |
| Unhealthy Days | 1 |
Natural Hazard Risk
| Overall Risk | Relatively Moderate |
| Risk Score | 89.7 / 100 |
| Social Vulnerability | 58.3 / 100 |
| Community Resilience | 45.1 / 100 |
Hazard Breakdown
| Tornado | Very Low |
| Earthquake | Relatively Moderate |
| Wildfire | Relatively Low |
| Flood | Relatively Moderate |
| Hail | Very Low |
| Strong Wind | Relatively Low |
| Heat Wave | Relatively Low |
| Winter Weather | Relatively Low |
| Lightning | Relatively Low |
| Ice Storm | Relatively Low |
| Drought | Very Low |
| Cold Wave | Very Low |
| Landslide | Relatively Moderate |
| Volcano | Relatively Moderate |
| Avalanche | Relatively High |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Tsunami History
4 tsunamis recorded within 500 km. Highest wave on record: 250.0 m (820 ft).
| Year | Location | Cause | Max Wave | Deaths | Distance |
| 1980 | WASHINGTON | Explosion | 250.0 m | 61 | 59 km |
| 1894 | PUYALLUP RIVER DELTA, TACOMA, WA | Meteorological | 3.0 m | 2 | 81 km |
| 1949 | PUGET SOUND, WA | Meteorological | 2.4 m | - | 81 km |
| 1949 | PUGET SOUND, WA | Eruption + Earthquake | - | 8 | 66 km |
Source: NOAA/NCEI Historical Tsunami Database. Sorted by wave height.
Nearby Volcanoes
6 volcanoes within 200 km. Closest: St. Helens (59 km).
| Name | Type | Elevation | Last Eruption | Distance |
| St. Helens | Stratovolcano | 2,549 m (8,363 ft) | 2008 | 59 km |
| Rainier | Stratovolcano | 4,392 m (14,409 ft) | 1450 | 79 km |
| West Crater | Volcanic field | 1,329 m (4,360 ft) | -5750 | 92 km |
| Indian Heaven | Shield(s) | 1,806 m (5,925 ft) | -6250 | 99 km |
| Adams | Stratovolcano | 3,742 m (12,277 ft) | 950 | 102 km |
| Hood | Stratovolcano | 3,426 m (11,240 ft) | 1866 | 155 km |
Source: Smithsonian Institution Global Volcanism Program (GVP). Sorted by distance.
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 41°F (5°C) | 8.1 in | |
| February | 43°F (6°C) | 5.8 in | |
| March | 47°F (8°C) | 6.3 in | |
| April | 51°F (11°C) | 5.5 in | |
| May | 57°F (14°C) | 3.8 in | |
| June | 61°F (16°C) | 2.7 in | |
| July | 66°F (19°C) | 0.9 in | Driest |
| August | 66°F (19°C) | 1.3 in | Warmest |
| September | 61°F (16°C) | 2.5 in | |
| October | 52°F (11°C) | 5.4 in | |
| November | 44°F (7°C) | 8.4 in | Wettest |
| December | 40°F (4°C) | 8.1 in | Coldest |
Onalaska has a seasonal temperature swing of 26°F / from 40°F in December to 66°F in August. Total annual precipitation is 58.7 inches, with November being the wettest month (8.4") and July the driest (0.9").