Leavenworth

Washington State Weather in September

Average temperatures, rainfall, sunshine and the best places to visit in Washington State, the United States of America in September.

Planning a journey to Washington State, the United States of America this September and curious over the weather conditions to await? Your essential details are found on this page, answering your query:

What to Expect in Washington State in September

Washington State, the United States of America is a region in the United States of America. Washington State, the United States of America offers a broad spectrum of weather patterns. In September, one might encounter temperatures that range from cold to warm, and precipitation levels ranging from low to high. September is a summer month.

Temperatures

The average maximum daytime temperatures vary from cold in Mount Rainier National Park at 8°C (46°F) to warm in Pasco at 27°C (81°F). Nighttime temperatures generally drop to 10°C (50°F) in Pasco and -3°C (27°F) in Mount Rainier National Park .

To learn more about the conditions in specific areas of Washington State, the United States of America, check out the map below.

Precipitation

In September, precipitation varies across different areas. From low rainfall in Moses Lake with an average of 6.1 mm (0.2 in) to high rainfall in Kalaloch with 139 mm (5.5 in).

Average sunshine

September brings good sunshine to many areas. Seattle sees around 220 hours of sunlight, great for visitors looking for bright days.

Explore Washington State by month

Pick a month to see the average temperature, rainfall and sunshine in Washington State - and find the best time to visit. (based on Seattle)

Best Places to Visit in Washington State in September

Click on a destination dot for more details. Toggle the map to compare temperatures or precipitation across Washington State.

perfect weather
pleasant
tolerable
unpleasant
poor

Perfect weather is subjective. On this map perfect weather has been defined with temperatures between 20°C (68°F) and 29°C (84°F) and not too much precipitation (less than 90 mm (3.5 in) a month).

Popular Destinations in Washington State

What is the weather like in September for some of the most popular destinations in Washington State, the United States of America?

Temperature range in Washington State (September)

Precipitation variation in Washington State (September)

Seattle

In September Seattle generally has pleasant temperatures with maximum daytime temperatures around 22°C (72°F), minimum nighttime temperatures around 12°C (54°F) and moderate monthly rainfall. So on average the conditions are excellent that month.

August
September
October
Max temperature
25°C (77°F)
22°C (72°F)
16°C (61°F)
Min temperature
14°C (57°F)
12°C (54°F)
8°C (46°F)
Monthly sun hours
280 hours
220 hours
143 hours
Monthly rainfall
23 mm (0.9 in)
49 mm (1.9 in)
100 mm (3.9 in)
Monthly rainy days
4 days
9 days
16 days
Weather conditions

SeaTac

In September SeaTac generally has pleasant temperatures with maximum daytime temperatures around 22°C (72°F), minimum nighttime temperatures around 12°C (54°F) and moderate monthly rainfall. So on average the conditions are excellent that month.

August
September
October
Max temperature
25°C (77°F)
22°C (72°F)
16°C (61°F)
Min temperature
14°C (57°F)
12°C (54°F)
8°C (46°F)
Monthly sun hours
280 hours
220 hours
143 hours
Monthly rainfall
22 mm (0.9 in)
49 mm (1.9 in)
99 mm (3.9 in)
Monthly rainy days
4 days
9 days
16 days
Weather conditions

Ocean Shores

In September Ocean Shores generally has pleasant temperatures with maximum daytime temperatures around 19°C (66°F), minimum nighttime temperatures around 11°C (52°F) and moderate monthly rainfall. So on average the conditions are very good that month.

August
September
October
Max temperature
19°C (66°F)
19°C (66°F)
15°C (59°F)
Min temperature
12°C (54°F)
11°C (52°F)
8°C (46°F)
Monthly rainfall
34 mm (1.3 in)
80 mm (3.1 in)
196 mm (7.7 in)
Monthly rainy days
9 days
13 days
19 days
Weather conditions

Bellevue

In September Bellevue generally has pleasant temperatures with maximum daytime temperatures around 22°C (72°F), minimum nighttime temperatures around 11°C (52°F) and moderate monthly rainfall. So on average the conditions are excellent that month.

August
September
October
Max temperature
25°C (77°F)
22°C (72°F)
16°C (61°F)
Min temperature
14°C (57°F)
11°C (52°F)
8°C (46°F)
Monthly sun hours
280 hours
220 hours
143 hours
Monthly rainfall
28 mm (1.1 in)
56 mm (2.2 in)
107 mm (4.2 in)
Monthly rainy days
6 days
10 days
16 days
Weather conditions

Vancouver

In September Vancouver generally has high temperatures with maximum daytime temperatures around 24°C (75°F), minimum nighttime temperatures around 11°C (52°F) and moderate monthly rainfall. So on average the conditions are excellent that month.

August
September
October
Max temperature
27°C (81°F)
24°C (75°F)
18°C (64°F)
Min temperature
14°C (57°F)
11°C (52°F)
7°C (45°F)
Monthly sun hours
298 hours
236 hours
152 hours
Monthly rainfall
12 mm (0.5 in)
41 mm (1.6 in)
85 mm (3.3 in)
Monthly rainy days
4 days
9 days
15 days
Weather conditions

Is your destination not in the list? Have a look at all destinations in Washington State, in the United States of America.

Popular cities in September

Day & night temperatures, rainfall and average weather in Washington State in September.

City Weather Day temp Night temp Rainfall
Seattle 22°C (72°F) 12°C (54°F) 49 mm (1.9 in)
SeaTac 22°C (72°F) 12°C (54°F) 49 mm (1.9 in)
Ocean Shores 19°C (66°F) 11°C (52°F) 80 mm (3.1 in)
Bellevue 22°C (72°F) 11°C (52°F) 56 mm (2.2 in)
Vancouver 24°C (75°F) 11°C (52°F) 41 mm (1.6 in)
Leavenworth 25°C (77°F) 8°C (46°F) 16 mm (0.6 in)

Washington State weather in September: frequently asked questions

What is the weather like in Washington State, the United States of America in September?

In September, Washington State, the United States of America generally has excellent weather conditions. Seattle sees daytime temperatures near 22°C (72°F), with nights cooling to roughly 12°C (54°F).

What is the average temperature in Washington State, the United States of America in September?

Average temperatures in Washington State, the United States of America during September range from a nighttime low near 12°C (54°F) to a daytime high around 22°C (72°F) in Seattle.

Does Washington State, the United States of America get a lot of rain in September?

Rain is generally moderate to light in Washington State, the United States of America during September, with Seattle averaging close to 49 mm (1.9 in).

Is September a Good Time to Visit Washington State, the United States of America?

We consider September to be one of the best times to travel to Washington State, the United States of America. Typically, the climate in Seattle is excellent. However, the weather conditions may vary depending on your destination.

Generally speaking, the best visiting conditions can be found in June, July, August and September offering mostly excellent weather in Seattle. On the other hand, the weather in January, February, March, November and December tend to be less favorable.

Interested in more climate information?

We have much more information about the climate in Washington State.

Weather and climate has detailed information for every country in the world. Are you going to the United States of America? Get detailed historical weather averages for many cities in the United States of America.

Not sure yet where to go? We now have a tool which recommends destinations that suit your ideal travel conditions. Find out where to go with our weather planner.

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