Rock Island, WA

Climate overview — based on NOAA 1991-2020 normals from WENATCHEE PANGBORN AP, WA US.

BWk Desert (cold) climate 7b USDA hardiness Zone 7b

Year-round temperatures (°F)

20° 40° 60° 80° J F M A M J J A S O N D
Avg high Avg low

Climate summary

Rock Island has an annual average temperature of 51.2°F with about 7.8 inches of precipitation per year. The warmest month is July (average high 87.6°F), and the coldest is January (average low 24.1°F). December is typically the wettest month (1.31 in) and August the driest (0.23 in).

Pleasant months
2 / 12
avg high 65–80°F, low ≥ 50°F
Annual swing
45.8°F
warmest to coldest month
Heating need
5,568
Cooling need
597

Best time to visit Rock Island

Full guide →

Climate change signal

All-time records →

66 of 366 (18%) of Rock Island's all-time daily heat records have been set since 2015. If records were spread evenly across the station's history, only about 5% would fall in any given decade.

1950s
2
1960s
70
1970s
56
1980s
43
1990s
67
2000s
33
2010s
61
2020s
34

Bars: number of all-time daily heat records still standing that were set in each decade.

Monthly averages

Month Avg High Avg Low Avg Temp Precipitation Snow Rainy days
January 33.6°F 24.1°F 28.9°F 1.02 in 9
February 41.6°F 27.4°F 34.5°F 0.76 in 7
March 52.5°F 33.7°F 43.1°F 0.73 in 6
April 61.8°F 40.4°F 51.1°F 0.57 in 5
May 71.6°F 48.7°F 60.1°F 0.77 in 6
June 78.2°F 54.9°F 66.5°F 0.50 in 5
July 87.6°F 61.8°F 74.7°F 0.24 in 3
August 86.4°F 61.0°F 73.7°F 0.23 in 2
September 76.7°F 52.5°F 64.6°F 0.23 in 3
October 60.5°F 40.9°F 50.7°F 0.62 in 6
November 43.8°F 30.9°F 37.4°F 0.85 in 8
December 33.4°F 24.5°F 29.0°F 1.31 in 11

Climate twins of Rock Island

Why these? →

The most climatically similar US cities at least 140 miles away (by monthly temperature + precipitation pattern).

Frost dates
Last spring / first fall frost
All-time records
Hottest, coldest, wettest
Planting calendar
What to plant, and when

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