Seattle Rainy Season: What Month Does it Rain the Most?

Seattle is famous for its rainy weather. However, the truth is that the rain in Seattle is widely misunderstood. In fact, you might be surprised to learn that across its summer months Seattle is closer to desert conditions!

Let’s dive into the Seattle rainy season. We’ll examine the rainiest months, the seasons you’ll want to avoid when visiting Seattle, and the best time to visit the city if you’re looking to stay dry.

When is the Rainy Season in Seattle?

Rain in Seattle
About 75% of rainfall in Seattle happens between October and March (max.ku/Shutterstock)

The rainy season in Seattle lasts from October to March. These six months contain 75% of Seattle’s annual rainfall! If you want to be even more specific, the three worst months for rain during the year are November, December, and January. These three months receive about 18 inches of rain combined.

However, rain is just the beginning of what makes these months a challenging time to live in Seattle. While Seattle has a relatively moderate climate (the daily mean temperature in these months ranges from 42 to 46.5 degrees Fahrenheit), these months receive very low amounts of sunshine.

In December, Seattle receives less than two hours of sunshine per day! Let’s compare how Seattle’s weather and rainy season compare to some other major cities across the country.

How Much Rain Does Seattle Receive Per Year?

Seattle Rainy Day
Rather than a high amount of annual rainfall, Seattle is notable for its number of rainy days (Bob Pool/Shutterstock)

It might surprise you that Seattle only receives 39.34 inches of rain per year. If you stack that up against other major cities in the United States, it doesn’t look so water-logged!

  • Miami: 67.41 inches
  • New Orleans: 63.35 inches
  • New York City: 49.52 inches
  • Washington DC: 41.82 inches
  • Chicago: 40.88 inches
  • Seattle: 39.34 inches
  • San Francisco: 22.89 inches

The Number of Rainy Days in Seattle Each year

Instead of receiving a high volume of rain, Seattle is frequently drizzly and overcast. If we compare this same list of cities on the number of days they receive rainfall (more than .01 inches), Seattle suddenly moves to the top of the pack.

  • Seattle: 156 rainy days per year
  • Miami: 141 rainy days per year
  • Chicago: 127 rainy days per year
  • New York City: 125 rainy days per year
  • Washington DC: 118 rainy days per year
  • New Orleans: 115 rainy days per year
  • San Francisco: 71 rainy days per year

That’s right, it rains an average of 156 days per year in Seattle. Months with more rain are also generally far more overcast, which means they’re also the months with lower amounts of sunshine.

Seattle Rainfall By Month

Seattle Rainfall By Month
Seattle’s rainfall peaks in the winter while its summers receive little rain (Data from NOAA)

The highest average rainfall Settle receives in a month is November, with 6.31 inches of rain. The lowest total is July, when Seattle averages just .60 inches. Put another way, it rains 10-fold as much in November as it does in July!

You can see the rainy season in Seattle very clearly when you examine the average rainfall by month:

  • January: 5.78 inches
  • February: 3.76 inches
  • March: 4.17 inches
  • April: 3.18 inches
  • May 1.88 inches
  • June: 1.45 inches
  • July: .60 inches
  • August: .97 inches
  • September: 1.61 inches
  • October: 3.91 inches
  • November: 6.31 inches
  • December: 5.72 inches

When is Seattle’s Dry Season?

Smoke Near Seattle
During September 2022 forest fires in the Cascades led to smoky air being trapped in Seattle. The city briefly had the worst measured air quality in the world.

The dry season in Seattle takes place from mid-June to mid-September. During this period rainfall averages only about one inch per month. This is also generally the best time to visit Seattle as the high level of sunshine and elevated temperatures make Seattle’s natural beauty more accessible.

It should be noted that there are some downsides to the low amounts of rain Seattle receives in the summer. For one, there are often droughts that require water conservation across the region. Another major problem that’s flared up in recent years is fires. During long droughts with higher temperatures, forest fires are an elevated risk in the mountains. The smoke from these fires sometimes collects in the Puget Sound region and leads to unhealthy air quality.

In 2021, Seattle went an astounding 55 straight days without rainfall during the summer. In 2022 it set a record hitting 80 degrees Fahrenheit in October, but the extended summer wasn’t enjoyed by locals as forest fires in the mountains created an extended period of unhealthy air conditions.

How Much Sunshine Does Seattle Get a Year?

Downtown Seattle View
Seattle gets less sunshine than most major US cities (f11photo/Shutterstock)

On average, Seattle gets 2,170 hours of sunshine per year. Compared to most major US cities, that’s not a lot. Once again, let’s compare Seattle to some other major US cities.

  • Miami: 3,154 hours of sunshine
  • San Francisco: 3,061 hours of sunshine
  • New Orleans: 2,659 hours of sunshine
  • New York City: 2,535 hours of sunshine
  • Washington DC: 2,527 hours of sunshine
  • Chicago: 2,508 hours of sunshine
  • Seattle: 2,170 hours of sunshine

Not surprisingly, the lowest amounts of sunshine happen during Seattle’s rainy season. For example, in December Seattle gets just 53 hours of sunshine (less than two hours per day on average!). That’s 24% as much sunshine as Miami, 33% as much as San Francisco, and just half Chicago’s December sunshine!

During the peak of summer, Seattle receives more sunshine than Miami. In July, the city gets 312 hours of sunshine, which averages out to about 10 hours per day and 65% of daylight hours.

The bottom line: If you’re looking to visit Seattle be aware that its rainy season stretches from October to March, with its worst periods in November through January. During this period there is little sunshine. While the rainstorms in Seattle are rarely as severe as East Coast rainstorms, these months tend to be extremely “drizzly” with long periods of rainfall and overcast skies.

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