Climate and monthly weather forecastSumner, WA
Climate and monthly weather forecast
Weather in January
January in Sumner, Washington, is a frosty winter month, with an average temperature ranging between min 33.1°F (0.6°C) and max 43.3°F (6.3°C). Sumner's average high-temperature in January is a frosty 43.3°F (6.3°C), marking an insignificant difference from the 41.4°F (5.2°C) of December. Weather in January »Weather in February
The last month of the winter, February, is another chilly month in Sumner, Washington, with an average temperature ranging between min 32.5°F (0.3°C) and max 43.7°F (6.5°C). Sumner's average high-temperature in February is a still chilly 43.7°F (6.5°C), marking an insignificant difference from the 43.3°F (6.3°C) of January. Weather in February »Weather in March
The first month of the spring, March, is also a frosty month in Sumner, Washington, with an average temperature ranging between max 48.6°F (9.2°C) and min 34.5°F (1.4°C). With March's advent, Sumner sees an average high-temperature of a still chilly 48.6°F (9.2°C), subtly shifted from February's 43.7°F (6.5°C). Weather in March »Weather in April
April is a fresh spring month in Sumner, Washington, with an average temperature fluctuating between 54°F (12.2°C) and 37.2°F (2.9°C). The shift from March to April introduces a subtle increase in the average high-temperature, moving from a frosty 48.6°F (9.2°C) to a cool 54°F (12.2°C). Weather in April »Weather in May
The last month of the spring, May, is an enjoyable month in Sumner, Washington, with an average temperature ranging between max 62.6°F (17°C) and min 41.5°F (5.3°C). The embrace of May brings a minor uplift in the average high-temperature, shifting from a fresh 54°F (12.2°C) in April to a refreshing 62.6°F (17°C). Weather in May »Weather in June
The first month of the summer, June, is still a refreshing month in Sumner, Washington, with temperature in the range of an average high of 67.3°F (19.6°C) and an average low of 45.1°F (7.3°C). The transition into June notes an average high-temperature of a still comfortable 67.3°F (19.6°C), revealing a mild distinction from the 62.6°F (17°C) in May. Weather in June »Weather in July
July in Sumner, Washington, is a moderately hot summer month, with an average temperature varying between 49.6°F (9.8°C) and 74.8°F (23.8°C). With the onset of July, Sumner's average high-temperature sees a modest rise, moving from June's refreshing 67.3°F (19.6°C) to a moderately hot 74.8°F (23.8°C). Weather in July »Weather in August
The last month of the summer, August, is also a moderately hot month in Sumner, Washington, with temperature in the range of an average low of 50.9°F (10.5°C) and an average high of 75.7°F (24.3°C). August stands out as Sumner's warmest month, with an average high-temperature of 75.7°F (24.3°C) and a low-temperature of 50.9°F (10.5°C). Weather in August »Weather in September
The first month of the autumn, September, is still a pleasant month in Sumner, Washington, with an average temperature ranging between max 68.9°F (20.5°C) and min 47.7°F (8.7°C). Sumner's weather subtly changes with the onset of September, barely falling from a warm 75.7°F (24.3°C) in August to an agreeable 68.9°F (20.5°C). Weather in September »Weather in October
October, the same as September, in Sumner, Washington, is another refreshing autumn month, with an average temperature fluctuating between 42.4°F (5.8°C) and 57.4°F (14.1°C). The onset of October entails a temperature shift, as the average high-temperature decreases from a pleasant 68.9°F (20.5°C) in September to a moderate 57.4°F (14.1°C). Weather in October »Weather in November
November, the last month of the autumn in Sumner, is another chilly month, with temperature in the range of an average high of 47.3°F (8.5°C) and an average low of 37°F (2.8°C). November suggests a modest reduction in the average high-temperature, shifting from a moderate 57.4°F (14.1°C) in October to a chilly 47.3°F (8.5°C). Weather in November »Weather in December
The first month of the winter, December, is also an icy month in Sumner, Washington, with an average temperature varying between 41.4°F (5.2°C) and 32°F (0°C). With average temperatures fluctuating between a high of 41.4°F (5.2°C) and a low of 32°F (0°C), December stands out as the coldest month. Weather in December »Updated: Aug 20, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
The most humid month is January, with an average relative humidity of 87%.
In Sumner, during the entire year, the rain falls for 185 days and collects up to 35.71" (907mm) of precipitation.
January through April, November and December are months with snowfall.
In Sumner, during the entire year, snow falls for 15.8 days and aggregates up to 9.09" (231mm) of snow.
The months with the lowest UV index are January, February, October through December, with an average maximum UV index of 2.
February is the month with the most snowfall. Snow falls for 5.3 days and accumulates 3.31" (84mm) of snow.
On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts, and the time zone changes from PST to PDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from PDT to PST.
In Sumner, snow does not fall in May through October.
June has the longest days of the year, with an average of 15h and 54min of daylight.
July and August, with an average relative humidity of 70%, are the least humid months.
The month with the least rainfall is July, when the rain falls for 7.6 days and typically collects 0.51" (13mm) of precipitation.
The month with the highest UV index is July, with an average maximum UV index of 5.
In Sumner, August is known for its average highest temperatures, reaching a high of 75.7°F (24.3°C) and a low of 50.9°F (10.5°C).
The month with the most sunshine is August, with an average of 10.9h of sunshine.
Sumner's coldest month, December, registers temperatures that range from a high of 41.4°F (5.2°C) to a low of 32°F (0°C).
December is the month with the most rainfall. Rain falls for 19.3 days and accumulates 5.35" (136mm) of precipitation.
December has the shortest days of the year, with an average of 8h and 36min of daylight.
The month with the least sunshine in Sumner is December, with an average of 4.2h of sunshine.
Average temperature
Sumner, WA
The warmest month (with the highest average high temperature) is August (75.7°F).
The month with the lowest average high temperature is December (41.4°F).
The month with the highest average low temperature is August (50.9°F).
The coldest month (with the lowest average low temperature) is December (32°F).
Average pressure
Sumner, WA
- Average pressure in January:
30.1"Hg - Average pressure in February:
30.06"Hg - Average pressure in March:
30.01"Hg - Average pressure in April:
30.05"Hg - Average pressure in May:
30.02"Hg - Average pressure in June:
30.02"Hg
- Average pressure in July:
30.03"Hg - Average pressure in August:
30"Hg - Average pressure in September:
30.01"Hg - Average pressure in October:
30.04"Hg - Average pressure in November:
30.05"Hg - Average pressure in December:
30.09"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is August (30"Hg).
Average wind speed
Sumner, WA
- Average wind speed in January:
4.9mph - Average wind speed in February:
4.7mph - Average wind speed in March:
4.8mph - Average wind speed in April:
4.3mph - Average wind speed in May:
3.9mph - Average wind speed in June:
3.8mph
- Average wind speed in July:
3.6mph - Average wind speed in August:
3.5mph - Average wind speed in September:
3.7mph - Average wind speed in October:
4.1mph - Average wind speed in November:
4.7mph - Average wind speed in December:
4.5mph
The windiest month (with the highest average wind speed) is January (4.9mph).
The calmest month (with the lowest average wind speed) is August (3.5mph).
Average humidity
Sumner, WA
The month with the highest relative humidity is January (87%).
The months with the lowest relative humidity are July and August (70%).
Average rainfall
Sumner, WA
- Average rainfall in January:
5.2" - Average rainfall in February:
3.62" - Average rainfall in March:
3.98" - Average rainfall in April:
2.83" - Average rainfall in May:
2.01" - Average rainfall in June:
1.54"
- Average rainfall in July:
0.51" - Average rainfall in August:
0.71" - Average rainfall in September:
1.61" - Average rainfall in October:
3.94" - Average rainfall in November:
4.41" - Average rainfall in December:
5.35"
The wettest month (with the highest rainfall) is December (5.35").
The driest month (with the least rainfall) is July (0.51").
Average rainfall days
Sumner, WA
- Average rainfall days in January:
18.6 days - Average rainfall days in February:
17.3 days - Average rainfall days in March:
20.7 days - Average rainfall days in April:
18.5 days - Average rainfall days in May:
14.8 days - Average rainfall days in June:
13.3 days
- Average rainfall days in July:
7.6 days - Average rainfall days in August:
6.8 days - Average rainfall days in September:
12.2 days - Average rainfall days in October:
16.4 days - Average rainfall days in November:
19.5 days - Average rainfall days in December:
19.3 days
The month with the highest number of rainy days is March (20.7 days).
The month with the least rainy days is August (6.8 days).
Average snowfall
Sumner, WA
The month with the highest snowfall is February (3.31").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days
Sumner, WA
- Average snowfall days in January:
2.8 days - Average snowfall days in February:
5.3 days - Average snowfall days in March:
2.9 days - Average snowfall days in April:
0.8 days - Average snowfall days in May:
0 days - Average snowfall days in June:
0 days
- Average snowfall days in July:
0 days - Average snowfall days in August:
0 days - Average snowfall days in September:
0 days - Average snowfall days in October:
0 days - Average snowfall days in November:
1.1 days - Average snowfall days in December:
2.9 days
The month with the highest number of snowfall days is February (5.3 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight / Average sunshine
Sumner, WA
- Average daylight in January:
9h and 0min - Average daylight in February:
10h and 18min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 42min - Average daylight in May:
15h and 6min - Average daylight in June:
15h and 54min
- Average daylight in July:
15h and 30min - Average daylight in August:
14h and 12min - Average daylight in September:
12h and 30min - Average daylight in October:
10h and 48min - Average daylight in November:
9h and 18min - Average daylight in December:
8h and 36min
The month with the longest days is June (Average daylight: 15h and 54min).
The month with the shortest days is December (Average daylight: 8h and 36min).
- Average sunshine in January:
4h and 18min - Average sunshine in February:
4h and 30min - Average sunshine in March:
6h and 0min - Average sunshine in April:
7h and 48min - Average sunshine in May:
9h and 0min - Average sunshine in June:
9h and 24min
- Average sunshine in July:
10h and 42min - Average sunshine in August:
10h and 54min - Average sunshine in September:
9h and 18min - Average sunshine in October:
5h and 30min - Average sunshine in November:
4h and 36min - Average sunshine in December:
4h and 12min
The month with the most sunshine is August (Average sunshine: 10h and 54min).
The month with the least sunshine is December (Average sunshine: 4h and 12min).
Average sunshine days
Sumner, WA
- Average sunshine days in January:
10.3 days - Average sunshine days in February:
8.2 days - Average sunshine days in March:
8.6 days - Average sunshine days in April:
9.2 days - Average sunshine days in May:
14.6 days - Average sunshine days in June:
13.8 days
- Average sunshine days in July:
21.7 days - Average sunshine days in August:
22 days - Average sunshine days in September:
16.9 days - Average sunshine days in October:
13.3 days - Average sunshine days in November:
8.8 days - Average sunshine days in December:
10.1 days
The month with the most sunshine days is August (22 days).
The month with the least sunshine days is February (8.2 days).
Average UV index
Sumner, WA
The month with the highest UV index is July (UV index 5).
The months with the lowest UV index are January, February, October, November and December (UV index 2).
Average cloud cover
Sumner, WA
The months with the most cloud cover are January and December (Cloud cover 56).
The month with the least cloud cover is August (Cloud cover 25).
Average visibility
Sumner, WA
The months with the highest visibility are July and August (6mi).
The months with the lowest visibility are January, February and December (4mi).
