Compare the Climate and Weather in Sumner, McChord Field Airport (Joint Base Lewis-McChord), and Seattle-Tacoma International Airport

This page lets you compare and contrast the weather and climate in Sumner, McChord Field Airport (Joint Base Lewis-McChord), and Seattle-Tacoma International Airport year round.

You can drill down to a specific season, month, and even day by clicking the graphs or using the navigation panel.

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Average High and Low Temperature

Compare the Average High and Low Temperature in Sumner, McChord Field Airport (Joint Base Lewis-McChord), and Seattle-Tacoma International AirportJanFebMarAprMayJunJulAugSepOctNovDec30°F30°F35°F35°F40°F40°F45°F45°F50°F50°F55°F55°F60°F60°F65°F65°F70°F70°F75°F75°F80°F80°F573780465534783044NowNowSumnerSumnerSeattle-Tacoma International AirportSeattle-Tacoma International AirportMcChord Field Airport (Joint Base Lewis-McChord)McChord Field Airport (Joint Base Lewis-McChord)
The daily average high and low air temperature at 2 meters above the ground. The thin dotted lines are the corresponding perceived temperatures.
HighJanFebMarAprMayJunJulAugSepOctNovDec
Sumner 48°F51°F55°F61°F67°F72°F79°F79°F73°F62°F52°F47°F
McChord Field Airport (Joint Base Lewis-McChord) 47°F50°F54°F60°F66°F71°F77°F78°F72°F61°F51°F46°F
Seattle-Tacoma International Airport 47°F50°F54°F59°F65°F71°F77°F77°F71°F60°F51°F46°F
LowJanFebMarAprMayJunJulAugSepOctNovDec
Sumner 37°F38°F40°F43°F48°F53°F56°F56°F52°F46°F41°F37°F
McChord Field Airport (Joint Base Lewis-McChord) 35°F36°F38°F41°F46°F51°F54°F54°F49°F44°F39°F35°F
Seattle-Tacoma International Airport 38°F39°F41°F44°F49°F53°F57°F57°F54°F48°F42°F38°F

Sumner

Average Hourly Temperature in SumnerJanFebMarAprMayJunJulAugSepOctNovDec12 AM12 AM4 AM4 AM8 AM8 AM12 PM12 PM4 PM4 PM8 PM8 PM12 AM12 AMNowNowvery coldvery coldcoldcoldcoolwarmcomfortable

McChord Field Airport (Joint Base Lewis-McChord)

Average Hourly Temperature in McChord Field Airport (Joint Base Lewis-McChord)JanFebMarAprMayJunJulAugSepOctNovDec12 AM12 AM4 AM4 AM8 AM8 AM12 PM12 PM4 PM4 PM8 PM8 PM12 AM12 AMNowNowvery coldvery coldcoldcoldcoolcomfortablewarm

Seattle-Tacoma International Airport

Average Hourly Temperature in Seattle-Tacoma International AirportJanFebMarAprMayJunJulAugSepOctNovDec12 AM12 AM4 AM4 AM8 AM8 AM12 PM12 PM4 PM4 PM8 PM8 PM12 AM12 AMNowNowvery coldvery coldcoldcoldcoolcomfortablewarm
frigid 15°F freezing 32°F very cold 45°F cold 55°F cool 65°F comfortable 75°F warm 85°F hot 95°F sweltering
The average hourly temperature, color coded into bands. The shaded overlays indicate night and civil twilight.

Chance of Clearer Skies

Compare the Chance of Clearer Skies in Sumner, McChord Field Airport (Joint Base Lewis-McChord), and Seattle-Tacoma International AirportJanFebMarAprMayJunJulAugSepOctNovDec0%0%10%10%20%20%30%30%40%40%50%50%60%60%70%70%80%80%90%90%100%100%762425NowNowSumnerSumnerSeattle-Tacoma International AirportSeattle-Tacoma International AirportMcChord Field Airport (Joint Base Lewis-McChord)McChord Field Airport (Joint Base Lewis-McChord)
The percentage of time the sky is clear, mostly clear, or partly cloudy (i.e., less than 60% of the sky is covered by clouds).
Clearer SkiesJanFebMarAprMayJunJulAugSepOctNovDec
Sumner 25%28%29%34%41%50%70%70%61%41%26%25%
McChord Field Airport (Joint Base Lewis-McChord) 25%28%30%36%43%53%72%71%62%43%28%25%
Seattle-Tacoma International Airport 28%31%33%38%45%53%70%70%62%44%30%28%

Daily Chance of Precipitation

Compare the Daily Chance of Precipitation in Sumner, McChord Field Airport (Joint Base Lewis-McChord), and Seattle-Tacoma International AirportJanFebMarAprMayJunJulAugSepOctNovDec0%0%10%10%20%20%30%30%40%40%50%50%60%60%70%70%80%80%90%90%100%100%598NowNowSumnerSumnerSeattle-Tacoma International AirportSeattle-Tacoma International Airport
The percentage of days in which precipitation is observed, excluding trace quantities.
Days of Precip.JanFebMarAprMayJunJulAugSepOctNovDec
Sumner 15.5d14.2d15.7d12.2d9.8d7.5d3.5d3.4d6.3d12.2d17.2d16.3d
McChord Field Airport (Joint Base Lewis-McChord) 15.1d13.7d15.0d11.7d9.3d7.1d3.3d3.3d6.3d11.9d16.8d16.0d
Seattle-Tacoma International Airport 15.0d13.6d15.1d11.8d9.3d7.3d3.6d3.5d6.5d12.1d16.7d16.0d

Average Monthly Rainfall

Compare the Average Monthly Rainfall in Sumner, McChord Field Airport (Joint Base Lewis-McChord), and Seattle-Tacoma International AirportJanFebMarAprMayJunJulAugSepOctNovDec0 in0 in2 in2 in4 in4 in6 in6 in8 in8 in10 in10 in8.60.67.9NowNowSumnerSumnerMcChord Field Airport (Joint Base Lewis-McChord)McChord Field Airport (Joint Base Lewis-McChord)
The average rainfall accumulated over the course of a sliding 31-day period centered on the day in question.
RainfallJanFebMarAprMayJunJulAugSepOctNovDec
Sumner 6.9″5.9″5.1″3.5″2.4″1.7″0.7″0.9″2.0″4.8″8.5″7.5″
McChord Field Airport (Joint Base Lewis-McChord) 6.5″5.7″4.9″3.4″2.2″1.6″0.7″0.8″1.9″4.6″8.1″7.1″
Seattle-Tacoma International Airport 6.1″5.3″4.6″3.2″2.2″1.6″0.7″0.9″1.9″4.5″7.7″6.7″

Average Monthly Snowfall

Compare the Average Monthly Snowfall in Sumner, McChord Field Airport (Joint Base Lewis-McChord), and Seattle-Tacoma International AirportJanFebMarAprMayJunJulAugSepOctNovDec0.0 in0.0 in0.5 in0.5 in1.0 in1.0 in1.5 in1.5 in2.0 in2.0 in1.42.02.0NowNowSumnerSumnerSeattle-Tacoma International AirportSeattle-Tacoma International AirportMcChord Field Airport (Joint Base Lewis-McChord)McChord Field Airport (Joint Base Lewis-McChord)
The average snowfall accumulated over the course of a sliding 31-day period centered on the day in question.
SnowfallJanFebMarAprMayJunJulAugSepOctNovDec
Sumner 1.1″0.3″0.0″0.0″0.0″0.0″0.0″0.0″0.0″0.0″0.2″1.0″
McChord Field Airport (Joint Base Lewis-McChord) 1.7″0.5″0.1″0.0″0.0″0.0″0.0″0.0″0.0″0.0″0.3″1.3″
Seattle-Tacoma International Airport 1.5″0.4″0.0″0.0″0.0″0.0″0.0″0.0″0.0″0.0″0.3″1.4″

Hours of Daylight

Compare the Hours of Daylight in Sumner, McChord Field Airport (Joint Base Lewis-McChord), and Seattle-Tacoma International AirportJanFebMarAprMayJunJulAugSepOctNovDec4 hr4 hr6 hr6 hr8 hr8 hr10 hr10 hr12 hr12 hr14 hr14 hr16 hr16 hr18 hr18 hr20 hr20 hr15.98.5NowNowSumnerSumnerSeattle-Tacoma International AirportSeattle-Tacoma International AirportMcChord Field Airport (Joint Base Lewis-McChord)McChord Field Airport (Joint Base Lewis-McChord)
The number of hours during which the Sun is at least partly above the horizon.
DaylightJanFebMarAprMayJunJulAugSepOctNovDec
Sumner 9.0h10.3h12.0h13.7h15.1h15.9h15.5h14.1h12.5h10.8h9.3h8.6h
McChord Field Airport (Joint Base Lewis-McChord) 9.0h10.3h12.0h13.7h15.1h15.9h15.4h14.1h12.5h10.8h9.3h8.6h
Seattle-Tacoma International Airport 9.0h10.3h12.0h13.7h15.2h15.9h15.5h14.2h12.5h10.8h9.3h8.5h

Chance of Muggy Conditions

Compare the Chance of Muggy Conditions in Sumner, McChord Field Airport (Joint Base Lewis-McChord), and Seattle-Tacoma International AirportJanFebMarAprMayJunJulAugSepOctNovDec0%0%10%10%20%20%30%30%40%40%50%50%60%60%70%70%80%80%90%90%100%100%NowNowSumnerSumner
The percentage of time that is muggy, oppressive, or miserable (i.e., a dew point greater than 65°F).
Muggy daysJanFebMarAprMayJunJulAugSepOctNovDec
Sumner 0.0d0.0d0.0d0.0d0.0d0.0d0.0d0.0d0.0d0.0d0.0d0.0d
McChord Field Airport (Joint Base Lewis-McChord) 0.0d0.0d0.0d0.0d0.0d0.0d0.0d0.0d0.0d0.0d0.0d0.0d
Seattle-Tacoma International Airport 0.0d0.0d0.0d0.0d0.0d0.0d0.0d0.0d0.0d0.0d0.0d0.0d

Average Wind Speed

Compare the Average Wind Speed in Sumner, McChord Field Airport (Joint Base Lewis-McChord), and Seattle-Tacoma International AirportJanFebMarAprMayJunJulAugSepOctNovDec0.0 mph0.0 mph0.5 mph0.5 mph1.0 mph1.0 mph1.5 mph1.5 mph2.0 mph2.0 mph2.5 mph2.5 mph3.0 mph3.0 mph3.5 mph3.5 mph4.0 mph4.0 mph4.5 mph4.5 mph5.0 mph5.0 mph5.5 mph5.5 mph6.0 mph6.0 mph5.33.03.2NowNowSumnerSumnerSeattle-Tacoma International AirportSeattle-Tacoma International AirportMcChord Field Airport (Joint Base Lewis-McChord)McChord Field Airport (Joint Base Lewis-McChord)
The average of mean hourly wind speeds at 10 meters above the ground.
Wind Speed (mph)JanFebMarAprMayJunJulAugSepOctNovDec
Sumner 5.14.94.64.13.63.43.13.13.54.15.15.2
McChord Field Airport (Joint Base Lewis-McChord) 5.04.94.74.33.83.63.33.33.74.35.15.1
Seattle-Tacoma International Airport 5.15.04.84.33.73.43.13.13.54.25.25.2

Average Water Temperature

Compare the Average Water Temperature in Sumner, McChord Field Airport (Joint Base Lewis-McChord), and Seattle-Tacoma International AirportJanFebMarAprMayJunJulAugSepOctNovDec46°F46°F48°F48°F50°F50°F52°F52°F54°F54°F56°F56°F58°F58°F5747NowNowSumnerSumnerSeattle-Tacoma International AirportSeattle-Tacoma International AirportMcChord Field Airport (Joint Base Lewis-McChord)McChord Field Airport (Joint Base Lewis-McChord)
The daily average wide-area surface water temperature.
Water Temp.JanFebMarAprMayJunJulAugSepOctNovDec
Sumner 47°F47°F47°F49°F52°F54°F56°F57°F56°F53°F51°F48°F
McChord Field Airport (Joint Base Lewis-McChord) 47°F47°F47°F49°F52°F54°F56°F57°F56°F53°F51°F48°F
Seattle-Tacoma International Airport 47°F47°F47°F49°F52°F54°F56°F57°F56°F53°F51°F48°F

Tourism Score

Compare the Tourism Score in Sumner, McChord Field Airport (Joint Base Lewis-McChord), and Seattle-Tacoma International AirportJanFebMarAprMayJunJulAugSepOctNovDec002244668810106.90.1NowNowSumnerSumnerSeattle-Tacoma International AirportSeattle-Tacoma International AirportMcChord Field Airport (Joint Base Lewis-McChord)McChord Field Airport (Joint Base Lewis-McChord)
The tourism score, which favors clear, rainless days with perceived temperatures between 65°F and 80°F.

Beach/Pool Score

Compare the Beach/Pool Score in Sumner, McChord Field Airport (Joint Base Lewis-McChord), and Seattle-Tacoma International AirportJanFebMarAprMayJunJulAugSepOctNovDec002244668810102.3NowNowSeattle-Tacoma International AirportSeattle-Tacoma International AirportMcChord Field Airport (Joint Base Lewis-McChord)McChord Field Airport (Joint Base Lewis-McChord)
The beach/pool score, which favors clear, rainless days with perceived temperatures between 75°F and 90°F.

Growing Season

Compare the Growing Season in Sumner, McChord Field Airport (Joint Base Lewis-McChord), and Seattle-Tacoma International AirportJanFebMarAprMayJunJulAugSepOctNovDec0%0%20%20%40%40%60%60%80%80%100%100%NowNowSumnerSumnerSeattle-Tacoma International AirportSeattle-Tacoma International Airport
The percentage chance that a given day is within the growing season, defined as the longest continuous period of non-freezing temperatures (≥ 32°F) in the year (the calendar year in the Northern Hemisphere, or from July 1 until June 30 in the Southern Hemisphere).

Growing Degree Days

Compare the Growing Degree Days in Sumner, McChord Field Airport (Joint Base Lewis-McChord), and Seattle-Tacoma International AirportJanFebMarAprMayJunJulAugSepOctNovDec500°F500°F1,000°F1,000°F1,500°F1,500°F2,000°F2,000°F2,500°F2,500°FNowNowSumnerSumnerSeattle-Tacoma International AirportSeattle-Tacoma International AirportMcChord Field Airport (Joint Base Lewis-McChord)McChord Field Airport (Joint Base Lewis-McChord)
The average growing degree days accumulated over the course of the year, where growing degree days are defined as the integral of warmth above a base temperature (50°F in this case).

Average Daily Incident Shortwave Solar Energy

Compare the Average Daily Incident Shortwave Solar Energy in Sumner, McChord Field Airport (Joint Base Lewis-McChord), and Seattle-Tacoma International AirportJanFebMarAprMayJunJulAugSepOctNovDec0 kWh0 kWh1 kWh1 kWh2 kWh2 kWh3 kWh3 kWh4 kWh4 kWh5 kWh5 kWh6 kWh6 kWh7 kWh7 kWh6.90.9NowNowSumnerSumnerSeattle-Tacoma International AirportSeattle-Tacoma International AirportMcChord Field Airport (Joint Base Lewis-McChord)McChord Field Airport (Joint Base Lewis-McChord)
The average daily shortwave solar energy reaching the ground per square meter.
Solar Energy (kWh)JanFebMarAprMayJunJulAugSepOctNovDec
Sumner 1.22.03.14.55.66.36.86.04.42.61.30.9
McChord Field Airport (Joint Base Lewis-McChord) 1.21.93.14.55.66.36.86.04.42.61.30.9
Seattle-Tacoma International Airport 1.22.03.14.55.66.26.75.94.42.61.30.9

This report illustrates the typical weather for Sumner, McChord Field Airport (Joint Base Lewis-McChord), and Seattle-Tacoma International Airport year round, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.

The details of the data sources used on this page vary between places and are discussed in detail on each place's dedicated page:

Disclaimer

The information on this site is provided as is, without any assurances as to its accuracy or suitability for any purpose. Weather data is prone to errors, outages, and other defects. We assume no responsibility for any decisions made on the basis of the content presented on this site.

We draw particular cautious attention to our reliance on the MERRA-2 model-based reconstructions for a number of important data series. While having the tremendous advantages of temporal and spatial completeness, these reconstructions: (1) are based on computer models that may have model-based errors, (2) are coarsely sampled on a 50 km grid and are therefore unable to reconstruct the local variations of many microclimates, and (3) have particular difficulty with the weather in some coastal areas, especially small islands.

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