How Often Does It Rain in Seattle? Let’s Check The Numbers

Seattle, Washington, often recognized for its cloudy skies and rainy days, has become somewhat notorious for its precipitation. When residents and visitors think of the city’s weather, they often associate it with persistent rainfall. Despite this reputation, there is more to the story of Seattle’s climate than just frequent showers.

So how often does it rain in Seattle? On average, Seattle experiences 156 rainy days per year, with the heaviest rainfall typically occurring in January, March, November, and December. While this number may seem high, Seattle’s total annual precipitation of 38 inches is actually on par with the US average. Interestingly, the city falls outside of the top 30 wettest major US cities, ranking 32nd among the nation’s 50 largest cities.

While it’s true that Seattle has a significant number of rainy days, the city’s reputation may be somewhat overstated. Understanding the nuances of Seattle’s climate and its actual rainfall statistics can provide a more accurate and well-rounded perspective on the city’s weather patterns.

Seattle’s Climate Overview

Seattle’s climate is characterized as a hybrid between oceanic and Mediterranean, influenced greatly by its location near the Puget Sound and the Cascade Mountains.

Temperature

The temperature ranges in Seattle are generally comfortable, with averages rarely falling below 21°F (-6°C) or rising above 94°F (34°C). Extreme temperatures beyond these values are rare occurrences. For instance, the most recent instances of temperatures below 15°F (-9°C) or above 97°F (36°C) were in November 2010 and June 2021, respectively.

Rainfall

Despite its reputation, Seattle does not experience constant rainfall. However, it does have its fair share of wet months. November receives the highest amount of precipitation, averaging around 6.3 inches of rainfall per year. On the contrary, July enjoys the least amount of rainfall, with just 0.6 inches. The best approach for outdoor activities in Seattle is to check the weather forecast for the day.

Month	Rainfall (inches)
January	5.1
February	3.9
March	3.7
April	2.7
May	2.0
June	1.5
July	0.6
August	0.9
September	1.7
October	3.4
November	6.3
December	5.6

Sunshine

Seattle experiences an average annual sunshine duration of approximately 2,170 hours. Summer months receive the most sunshine, with up to 312 hours recorded in July. This complements the low rainfall during the summer season, making it the best time of year for outdoor activities in the city. Winter months, however, receive significantly less sunshine, with around 52 hours of sunlight in December.

In conclusion, Seattle’s climate features a unique blend of oceanic and Mediterranean influences, leading to mild temperatures and varying rainfall patterns throughout the year. While it does not constantly rain in the city, it is essential to consider the weather forecast when planning activities in Seattle.

Rain by Season

Winter

Seattle experiences chilly, rainy winters with the most precipitation occurring in December, January, and February. On average, December is the rainiest month with about 6.3 inches of rainfall, while January and February experience around 18 inches of rain combined. Snowfall of about 1.7 inches is not unusual, mainly occurring in December and February. During the winter months, Seattle’s average humidity is 79%, and the city typically receives only two hours of sunshine per day.

Spring

Springtime in Seattle is also quite rainy, with a 33% chance of precipitation. Rainfall decreases gradually as spring progresses, making way for the drier summer months. While the number of rainy days in spring is higher compared to other seasons, the intensity of rainfall is relatively lower.

Summer

Summer in Seattle is comparatively drier, with the least amount of rain occurring from June to August. July is the driest month, averaging only 0.6 inches of rain. The likelihood of precipitation during the summer season drops to around 10% of what occurs in November.

Autumn

Autumn in Seattle experiences the lowest chance of rainfall among all seasons, with only a 13% chance of a rainy day. However, as the season progresses into October and November, the probability of rain begins to increase, marking the beginning of the rainy season that lasts through to March.

Comparing Rainfall to Other US Cities

When discussing rainfall in Seattle, comparing it to other major cities in the United States is important. While Seattle is often perceived as one of the rainiest cities, it does not even rank in the top 30 of the nation’s 50 largest cities in terms of precipitation.

Seattle experiences an average of 156 rainy days per year. Compared to some other major cities, this number is fairly modest. Here are a few striking comparisons:

• 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
• Atlanta: 114 rainy days per year
• San Francisco: 71 rainy days per year

Seattle’s rainiest season is spring, with 33% of its annual rainfall occurring during this time. Autumn is the city’s driest season, with only a 13% chance of a rainy day.

It is also worth noting that while Seattle has more rainy days than some of these mentioned cities, the actual volume of rain it receives can be lower. This means that, although it rains more frequently, the showers in Seattle tend to be lighter and less intense.

In conclusion, when comparing rainfall to other major US cities, Seattle does not hold the title for the highest amount of precipitation. While it has a reputation for frequent showers, it does not outpace its counterparts in terms of total rainfall or even fall within the top 30 rainiest cities in the United States.

Understanding Seattle’s Rain Patterns

Rainy Days vs. Drizzle

Seattle is quite well-known for its rainy weather, but it’s important to differentiate between rainy days and drizzle. Rainy days in Seattle typically consist of raindrops measuring about 0.5 mm (0.02 inches) in diameter, whereas drizzle is characterized by smaller drops. Seattle experiences precipitation in various forms, with 155 days per year on average receiving some kind of precipitation.

Rain Shadow and Mountains

One contributing factor to Seattle’s rain patterns is the presence of the Olympic Mountains, which play a significant role in creating a rain shadow effect. The rain shadow effect occurs when moist air moves over the mountains, losing moisture as it rises and cools, and leaving the other side of the mountains with much less precipitation. In the Seattle area, this causes the western side of the Olympic Mountains to receive more rainfall, while areas further east are protected and receive less rain.

Location	Average Rainfall
Western Olympics	120-180 inches
Eastern Olympics	60-80 inches
Seattle	38 inches

Lake Washington and the Pacific Ocean

The proximity of Seattle to both Lake Washington and the Pacific Ocean also plays a role in its weather patterns. As weather systems move in from the Pacific, they can become intensified by interactions with the large lake and ocean waters, in turn leading to higher amounts of rainfall in some areas of Seattle. The city’s precipitation also varies by month, with November being the rainiest month, receiving an average of 6.3 inches of rain, whereas July is the least rainy with only 0.6 inches.

Understanding the various factors contributing to Seattle’s rain patterns, such as the distinction between rainy days and drizzle, the influence of the Olympic Mountains, and the proximity to Lake Washington and the Pacific Ocean, provides a clearer picture of the city’s unique weather conditions.

Outdoor Activities in Seattle’s Rainy Weather

Best Time for Outdoor Activities

In Seattle, known as the Emerald City, the rainfall is quite frequent, with an average of 156 rainy days per year. Despite the rainy reputation, there are still plenty of outdoor activities to enjoy in Seattle. The best time for outdoor activities in Seattle is typically during the summer months, when there are longer daylight hours and better air quality.

Hiking and Walks

Seattle offers numerous hiking and walking trails, even during its rainy season. Some popular trails include:

• Discovery Park Loop Trail, which offers stunning views of the Olympic Mountains and Puget Sound
• Green Lake Loop, a paved path that circles the beautiful Green Lake
• Washington Park Arboretum, providing a walk among various tree species and seasonal blooms

When planning a hike or walk in Seattle, make sure to check the weather forecast and come prepared with proper rain gear. It’s always a good idea to carry a waterproof jacket, wear water-resistant shoes, and pack extra layers in case the weather changes.

Swimming and Lakes

Although Seattle isn’t known for its warm climate, swimming can still be enjoyed in some of its local lakes during the summer months. Water temperatures typically range from 55°F (13°C) to 65°F (18°C), making it refreshing for a quick dip. Some popular lakes for swimming in Seattle include:

• Green Lake, which features a designated swimming area and lifeguard supervision during summer months
• Lake Washington, offering several beach parks with swimming areas, such as Matthews Beach and Madison Park Beach
• Alki Beach, located along the shores of Puget Sound, provides a beautiful view of the Space Needle while swimming

Keep in mind that air and water temperatures in Seattle can vary, so it’s essential to check weather and water conditions before heading out for a swim.

Overall, visiting Seattle during its rainy season shouldn’t deter outdoor enthusiasts. With the right preparation and knowledge of local activities, visitors can thoroughly enjoy their time in Seattle, rain or shine.

Weather Tips for Visiting Seattle

Packing Outerwear and Essentials

When visiting Seattle, it’s essential to be prepared for its unpredictable weather. The city experiences a mix of rain, fog, and sunshine throughout the year. The average annual rainfall in Seattle is approximately 37 inches, making it a wetter city than many others in the US. In winter and spring, the weather tends to be colder and wetter, while the drier and warmer months occur in July, August, and September.

When packing outerwear, consider including the following items:

• Waterproof jackets or raincoats
• Umbrellas
• Moisture-wicking clothing
• Comfortable, waterproof shoes
• Warm layers for cooler temperatures, especially in the rainy seasons

Don’t forget to pack essentials such as sunglasses and sunscreen, as the city does experience occasional sunny days.

Festivals and Activities for Rainy Days

Rainy days in Seattle are common, but there’s still plenty to do and see. The city offers a variety of indoor activities and events to keep you entertained when the weather doesn’t cooperate. Some popular festivals and activities to consider during your visit include:

• Seattle International Film Festival (SIFF): Typically held in late spring, this annual event showcases a diverse range of films from around the world.
• Seattle Art Museum: The expansive museum offers exhibitions covering various genres, cultures, and time periods, providing a perfect escape from the rain.
• Pike Place Market: Explore the indoor marketplace, which offers an array of food, crafts, and other unique commodities from local vendors.
• Chihuly Garden and Glass: View stunning glass artwork crafted by renowned artist Dale Chihuly, housed in a beautiful indoor gallery.
• The Museum of Pop Culture (MoPOP): Dive into the history of music, movies, and other creative arts in this interactive museum.

Despite the wet climate, Seattle’s unique geographic location between Puget Sound and the Cascade Mountains offers a lush, green landscape perfect for exploring. Whether admiring the city’s many parks, attending cultural events, or simply staying warm indoors, visitors can experience the beauty and vibrancy of Seattle, rain or shine.