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Sumner (WA) Weather and Climate: A Comprehensive Guide

Sumner experiences great temperature shifts. The city's weather can transition from warm days to cold weather. It also has a notably wet climate with much precipitation. Now, let’s break down all the climate details for a clearer picture.

Average maximum day and minimum night temperature

The climate in Sumner is known for significant temperature differences throughout the year, making the weather dynamic. Average maximum daytime temperatures range from a comfortable 25°C in August, the warmest time of the year, to a chilly 8°C during cooler months like December.

At night, temperatures typically drop to an average of around 1°C during these months. Check out our detailed temperature page for more information.

Temperature ranges by month

Precipitation and rainy days

Sumner has a notably wet climate with abundant precipitation, recording 1119 mm of rain/snowfall per year. Significant seasonal changes in precipitation occur throughout the year. During the wetter season, November receives heavy rainfall, averaging 176 mm of precipitation, recorded across 21 rainy days. In contrast, the drier season, July brings less rainfall, with 18 mm over 6 rainy days. For more details, please visit our Sumner Precipitation page.

The mean monthly precipitation over the year, including rain, hail and snow

Sunshine over the year

Seasonal changes in sunshine hours are quite dramatic in Sumner. While July receives considerable daily sunshine with up to 10.4 hours, November marks the darkest time of the year, where sunshine is scarce with only 2.0 hours of sunlight per day. Visit our detailed sunshine hours page for more information.

Monthly hours of sunshine

Data from: Tacoma, the United States of America (16 KM, 10 Miles).

Daily hours of sunshine

Data from: Tacoma, the United States of America (16 KM, 10 Miles).

Forecast for Sumner (WA)

Fri   Dec 27
10°C | 5°C
SW 4 m/s
14 mm
overcast and rain

overcast and rain

Sat   Dec 28
11°C | 6°C
SW 7 m/s
11 mm
overcast and heavy rain

overcast and heavy rain

Sun   Dec 29
9°C | 5°C
SE 3 m/s
6.2 mm
broken clouds and rain

broken clouds and rain

The best time of year to visit Sumner in the United States of America

During the months of June, July, August and September you are most likely to experience good weather with pleasant average temperatures that fall between 20°C and 26°C.

Other facts from our historical weather data:
  • Which months have the greatest rainfall in Sumner?
    Most rainfall (rainy season) is seen in January, November and December.
  • Which is the warmest month in Sumner?
    August has an average maximum temperature of 25°C and is the warmest month of the year.
  • Which is the coldest month in Sumner?
    The coldest month is December with an average maximum temperature of 8°C.
  • Which is the wettest month in Sumner?
    November tops the wettest month list with 176 mm of rainfall.
  • Which is the driest month in Sumner?
    July is the driest month with 18 mm of precipitation.
  • Which is the sunniest month in Sumner?
    July is the sunniest month with an average of 312 hours of sunshine.

  • No idea where to travel to this year? We have a tool that recommends destinations based on your ideal conditions. Find out where to go with our weather planner.