What is the hottest month in Seattle?

August is Seattle's hottest month, with the highest average daily high of the year. The month-by-month table above shows Seattle's exact average high and low for each month, based on the 1991–2020 climate normals — the standard 30-year reference period meteorologists use.

What is the coldest month in Seattle?

December is Seattle's coldest month, with the lowest average daily low of the year. The averages-by-month chart above gives the exact average high and low for every month, so you can see how cold a typical winter day runs.

How much does it rain in Seattle?

Seattle's total annual precipitation and its wettest and driest months are shown in the rainfall-by-month section above. Those figures are 1991–2020 normals — the average monthly precipitation total across that 30-year window — so they reflect a typical year rather than any single wet or dry season.

What months are best to visit Seattle?

The most comfortable months in Seattle are usually the shoulder seasons — spring and fall — when temperatures sit between the summer peak and winter low and rainfall is moderate. Compare the average high, low, and precipitation for each month in the table above to pick the window that fits the weather you want.

Has Seattle gotten hotter?

There isn't enough data to say. The warming-stripes chart above plots Seattle's annual mean temperature for every complete year of station data from 1948 to 2025, but no trend line is fitted: the latest stretch of complete years with no gap over 10 years is 1999–2025, only 26 years (a trend needs at least 30). A shorter or broken record can't separate a climate trend from normal year-to-year swings.

What is the record high temperature in Seattle?

Seattle's all-time record high — the hottest single day in the station record — is shown in the records section above, along with the date it occurred. Records are drawn from the nearest long-term weather station's full daily history, which begins in 1948, so they capture the most extreme heat on record, not just a typical summer day.

What is the record low temperature in Seattle?

Seattle's all-time record low and the date it was set appear in the records section above. Like the record high, it comes from the station's full daily history back to 1948, so it reflects the coldest day on record rather than an average winter low.

Seattle, Washington Climate

Seattle weather by month — average highs and lows, rainfall, all-time records, and the warming record since 1948

Hottest month: 77°FAugust average high
Coldest month: 36°FDecember average low
Precipitation: 36.5 ina year
Wettest month: November5.8 in on average

1991–2020 NOAA climate normals

At 10:37 PM PDT on Sep 20 it was 55°F in Seattle — 6° below the 61°F typical for that hour (estimated from the Sep 20 normal high of 70°F and low of 53°F, interpolated from the monthly normals).

Seattle weather by month

Average high, low, and rainfall for every month, from Seattle’s 1991–2020 climate normals, the standard 30-year reference period. Each band runs from the month’s average low to its average high: a tall band is a big day-to-night swing.

49°37°

5.2″Jan

51°37°

3.7″Feb

55°39°

3.9″Mar

60°44°

2.9″Apr

67°49°

2.0″May

71°54°

1.2″Jun

77°58°

0.6″Jul

77°58°

0.8″Aug

72°54°

1.4″Sep

61°46°

3.5″Oct

53°40°

5.8″Nov

48°36°

5.5″Dec

Average high → low (°F)Rainfall (inches)1991–2020 normals

Seattle monthly weather averages — average high, average low, and rainfall for each month, from the 1991–2020 U.S. Climate Normals (NOAA).
Month	Avg High	Avg Low	Rainfall
January	49°F	37°F	5.2 in
February	51°F	37°F	3.7 in
March	55°F	39°F	3.9 in
April	60°F	44°F	2.9 in
May	67°F	49°F	2.0 in
June	71°F	54°F	1.2 in
July	77°F	58°F	0.6 in
August	77°F	58°F	0.8 in
September	72°F	54°F	1.4 in
October	61°F	46°F	3.5 in
November	53°F	40°F	5.8 in
December	48°F	36°F	5.5 in
Annual	62°F	46°F	36.5 in

Seattle’s warming record since 1948

No trend published: the latest stretch of complete years with no gap over 10 years is 1999–2025, only 26 years (a trend needs at least 30)Gaps are years with incomplete station data.

Not what a typical year looks like, but how the typical year has changed. Each stripe is one complete year’s average temperature at the station, 1948 to 2025, colored against the mean of those years: blue for cooler years, red for warmer ones. No trend line is fitted to them: the latest stretch of complete years with no gap over 10 years is 1999–2025, only 26 years (a trend needs at least 30).

Seattle rainfall by month

Seattle averages 36.5 inches of precipitation a year. The wettest month is November and the driest is July.

Seattle temperature records

All-time record high: 105°Fset July 29, 2009
All-time record low: 3°Fset January 31, 1950

Records are drawn from the nearest long-term weather station’s full daily history, so they capture the most extreme single day Seattle has recorded — not a typical seasonal high or low.

Frequently asked

What is the hottest month in Seattle?: August is Seattle's hottest month, with the highest average daily high of the year. The month-by-month table above shows Seattle's exact average high and low for each month, based on the 1991–2020 climate normals — the standard 30-year reference period meteorologists use.
What is the coldest month in Seattle?: December is Seattle's coldest month, with the lowest average daily low of the year. The averages-by-month chart above gives the exact average high and low for every month, so you can see how cold a typical winter day runs.
How much does it rain in Seattle?: Seattle's total annual precipitation and its wettest and driest months are shown in the rainfall-by-month section above. Those figures are 1991–2020 normals — the average monthly precipitation total across that 30-year window — so they reflect a typical year rather than any single wet or dry season.
What months are best to visit Seattle?: The most comfortable months in Seattle are usually the shoulder seasons — spring and fall — when temperatures sit between the summer peak and winter low and rainfall is moderate. Compare the average high, low, and precipitation for each month in the table above to pick the window that fits the weather you want.
Has Seattle gotten hotter?: There isn't enough data to say. The warming-stripes chart above plots Seattle's annual mean temperature for every complete year of station data from 1948 to 2025, but no trend line is fitted: the latest stretch of complete years with no gap over 10 years is 1999–2025, only 26 years (a trend needs at least 30). A shorter or broken record can't separate a climate trend from normal year-to-year swings.
What is the record high temperature in Seattle?: Seattle's all-time record high — the hottest single day in the station record — is shown in the records section above, along with the date it occurred. Records are drawn from the nearest long-term weather station's full daily history, which begins in 1948, so they capture the most extreme heat on record, not just a typical summer day.
What is the record low temperature in Seattle?: Seattle's all-time record low and the date it was set appear in the records section above. Like the record high, it comes from the station's full daily history back to 1948, so it reflects the coldest day on record rather than an average winter low.