Washington Climate & Monthly Temperature Overview – United States

Summer in Washington

Washington state experiences warm and sunny summers, with average high temperatures ranging from the mid-60s to low-70s. The Pacific Ocean’s influence brings cool breezes to the coastal areas, while inland temperatures can rise slightly higher. July and August are typically the warmest months, with minimal rainfall and plenty of sunshine. This makes summer an ideal time for outdoor activities such as hiking, camping, and swimming. However, the occasional heat wave can bring temperatures into the 80s or even 90s, so it’s best to stay hydrated and seek shade during the hottest part of the day.

Winter in Washington

In contrast to its warm summers, Washington has mild winters with average high temperatures in the low-40s. The Pacific Ocean’s moderating influence keeps temperatures from dropping too low, even in the coldest months. Precipitation is common in the form of rain or snow, especially in the western part of the state. Due to the higher elevation in the Cascade Mountains, snow accumulation can be significant in the mountain passes and ski resorts, providing ample opportunities for winter sports enthusiasts. Coastal areas tend to have milder winters, with occasional freezing temperatures and frost.

Yearly Averages

Washington state experiences a varied climate, influenced by its geography and proximity to the Pacific Ocean. The average temperature in Washington varies depending on the region and altitude, but generally ranges from the mid-40s to the low 60s Fahrenheit (7 to 17 degrees Celsius). The coastal regions tend to be milder, with average temperatures in the mid-50s to low 60s Fahrenheit (13 to 17 degrees Celsius), while the eastern regions experience a more continental climate with average temperatures in the mid-40s to low 50s Fahrenheit (7 to 13 degrees Celsius).

Seasonal Variations

Washington state has four distinct seasons: spring, summer, autumn, and winter. Spring typically brings mild temperatures, with average highs in the mid-50s to low 60s Fahrenheit (13 to 17 degrees Celsius) and average lows in the upper 30s to low 40s Fahrenheit (3 to 7 degrees Celsius). Summer is generally warm and dry, with average highs in the mid-70s to low 80s Fahrenheit (24 to 28 degrees Celsius) and average lows in the mid-50s to low 60s Fahrenheit (13 to 17 degrees Celsius). Autumn brings cooler temperatures, with average highs in the mid-50s to low 60s Fahrenheit (13 to 17 degrees Celsius) and average lows in the mid-30s to low 40s Fahrenheit (3 to 7 degrees Celsius). Winter is characterized by cold and wet conditions, with average highs in the mid-40s to low 50s Fahrenheit (7 to 13 degrees Celsius) and average lows in the mid-30s to low 40s Fahrenheit (3 to 7 degrees Celsius).

Cloud Distribution and Patterns

Washington experiences a diverse range of cloud types due to its varied topography and weather patterns. Western Washington, with its proximity to the Pacific Ocean, is characterized by frequent overcast skies and abundant clouds. The terrain of the Cascades Mountains, which run north-south through the state, influences cloud distribution, causing clouds to form and dissipate as they encounter the rugged mountain peaks. Eastern Washington, on the other hand, is drier and experiences fewer clouds, particularly during the summer months.

Impact on Climate and Weather

Clouds play a significant role in the climate and weather of Washington. The persistent cloud cover in Western Washington moderates temperatures, preventing extreme heat or cold. Overcast skies can also contribute to gloomy or drizzly conditions, especially during the winter months. In Eastern Washington, where clouds are less prevalent, temperatures tend to be more extreme and the sky is often clear. Clouds can also affect precipitation patterns, with some areas of the state receiving more rainfall or snowfall due to cloud formation and precipitation release.

Annual Precipitation Patterns

Washington state experiences significant variation in annual precipitation, influenced by its diverse topography and proximity to the Pacific Ocean. Western Washington, where the Olympic Mountains and Cascade Range intercept moisture-laden winds from the ocean, receives abundant rainfall averaging over 80 inches per year. Seattle, the largest city in the state, receives approximately 38 inches of rain annually, contributing to its reputation as a rainy city. In contrast, Eastern Washington, sheltered by these mountain ranges, has a much drier climate with annual precipitation below 20 inches in certain areas.

Seasonal Precipitation

Precipitation in Washington exhibits a distinct seasonal pattern. Western Washington receives substantial rainfall from October to April, with November being the wettest month. During this period, frequent storms bring heavy downpours and contribute to the lush greenery that characterizes the region. In contrast, Eastern Washington experiences drier conditions during the winter months but receives some precipitation in the form of snow. Spring and fall generally bring moderate rainfall to both Western and Eastern Washington. However, in summer, Western Washington enjoys relatively dry weather, while Eastern Washington tends to be hotter and drier, with occasional thunderstorms.

Climate Variability

Washington experiences significant climate variability due to its diverse geography. The western part of the state, including Seattle and the Olympic Mountains, receives abundant rainfall year-round, with an average annual precipitation exceeding 100 inches. This region is influenced by the moist Pacific air masses that produce frequent drizzle and cool temperatures. Eastern Washington, on the other hand, has a much drier climate, with some areas receiving less than 10 inches of rainfall annually. The Cascade Mountains act as a barrier, blocking the moist air from the Pacific from reaching the eastern slopes. As a result, Eastern Washington experiences hot, dry summers and cold, snowy winters.

Causes of Rainfall Patterns

The rainfall patterns in Washington are primarily influenced by three factors: altitude, proximity to the ocean, and prevailing wind patterns. High-elevation areas, such as the Olympic Mountains and Cascade Mountains, receive more precipitation because the air rises as it crosses the slopes, cooling and condensing. Areas closer to the Pacific Ocean, such as Seattle and the western coast, receive more rainfall due to the proximity to the moisture source. Additionally, the prevailing westerly winds from the Pacific bring moisture to the western part of the state, while the eastern part is shielded by the Cascade Mountains, resulting in a drier climate.

Annual Snowfall

Washington state experiences varying annual snowfall depending on the region. In the west, the Olympic Mountains and Cascade Range accumulate significant snow. Mount Baker, located in the North Cascades, holds the record for the highest snowfall in the contiguous United States, averaging over 500 inches per year. The western slopes of the Cascade Mountains typically receive between 100 to 300 inches of snow annually. However, the eastern slopes, known as the Okanogan Highlands, have a much drier climate and receive significantly less snowfall, often less than 10 inches per year.

Seasonal Variations

The snowfall in Washington also varies significantly throughout the year. Winter months, from November to February, typically witness the heaviest snowfall. January is usually the snowiest month, with the mountains receiving the highest accumulations. During this period, major storms can dump several feet of snow, leading to road closures and power outages. As spring approaches, snowfall gradually decreases. By April, most of the snowpack has melted in the lower elevations, while snow lingers in the mountains until May or June.

Sunrise and Sunset

In Washington, United States, the sunrise and sunset times vary significantly throughout the year due to the Earth’s tilt and the planet’s rotation. During the summer months, the sun rises earlier and sets later, resulting in longer days with more daylight hours. The earliest sunrise occurs in mid-June, around 4:30 AM, while the latest sunset happens in late June, around 8:45 PM. In contrast, during the winter months, the sun rises later and sets earlier, leading to shorter days with fewer daylight hours. The latest sunrise takes place in mid-December, around 7:30 AM, and the earliest sunset falls in mid-December, approximately 4:30 PM.

Sunlight Hours

The number of sunlight hours in Washington, United States, also fluctuates throughout the year. During the summer months, when the days are longer, Washington experiences an average of 16 hours of sunlight per day. This ample sunshine duration provides ample opportunities for outdoor activities, such as hiking, biking, and swimming. In contrast, during the winter months, when the days are shorter, Washington receives an average of only 8 hours of sunlight per day. The limited daylight can impact daily schedules and make it more challenging to engage in outdoor activities during this time.

Moonrise and Moonset

In the bustling city of Washington, D.C., the moon’s ethereal glow enhances the city’s iconic skyline. The moon’s rise and set times vary throughout the year, offering celestial spectacles to observe. During the winter months, the moon rises earlier in the evening, often casting a gentle glow on the monuments and memorials. In the summer months, the moon’s ascent occurs later, illuminating the city as it stirs from sleep. Similarly, the moon’s descent follows a seasonal pattern, disappearing below the horizon at different hours depending on the time of year.

Phases of the Moon

The moon’s ever-changing phases add an element of celestial beauty to Washington’s landscape. From the crescent moon’s delicate arc to the full moon’s luminous orb, each phase presents a unique celestial display. During the new moon, the moon is not visible, as it aligns between the Earth and the Sun. As the moon waxes, it gradually transforms into a crescent, then a quarter moon, and eventually reaches its full glory as a full moon. The waning moon then undergoes the reverse process, slowly shrinking back into a crescent before disappearing once more in the darkness of the new moon.

Seasonal Humidity Trends

Washington, United States, experiences a wide range of humidity conditions throughout the year. During the summer months (June-August), the humidity levels soar due to warm temperatures and frequent rainfall. The average relative humidity during this period is around 70%, with some days reaching as high as 90%. This high humidity can make outdoor activities uncomfortable and contribute to a feeling of mugginess.

Winter Dryness

In contrast to the humid summers, Washington’s winters (December-February) are characterized by significantly lower humidity levels. The cold temperatures result in less moisture in the air, leading to average relative humidity values below 60%. This dryness can cause discomfort and irritation in the skin and respiratory system. It is important to use humidifiers indoors during the winter months to maintain a comfortable indoor environment.

Coastal vs. Inland Humidity

Washington’s coastal regions, such as Seattle and Bellingham, tend to have higher humidity levels throughout the year compared to inland areas. The proximity to the ocean provides a steady source of moisture, contributing to an average relative humidity of 70-80%. In contrast, inland cities like Spokane and Yakima experience lower humidity levels, averaging around 60-70% during most of the year.

Wind Speed and Seasonality

Washington state in the United States experiences a wide range of wind speeds throughout the year. In general, the highest wind speeds occur during the winter months, particularly along the Pacific coast. During this time, the region is under the influence of strong westerly winds known as the prevailing westerlies. These winds can reach speeds of up to 50 miles per hour in coastal areas. In contrast, the summer months tend to be calmer, with average wind speeds dropping to around 10-15 miles per hour. The eastern part of the state, including the Cascade Mountains, generally experiences higher wind speeds than western regions due to the influence of the terrain.

Wind Energy Potential

Washington state has a significant wind energy potential due to its abundance of windy areas. The state ranks among the top in the nation for wind power generation, with installed capacity exceeding 3,000 megawatts. The windiest area in the state is the Columbia River Gorge, where wind farms have been developed to harness the strong and steady winds that flow through the narrow canyon. Other areas with high wind energy potential include the coastline, the San Juan Islands, and the Cascade Mountains. The development of wind energy in Washington has contributed to reducing the state’s reliance on fossil fuels and promoting renewable energy sources.

Spring (March-May)

Spring in Washington brings with it a burst of color as blooming cherry blossoms paint the city in shades of pink and white. Temperatures range from mild to warm, with occasional showers. While the cherry blossoms are the main attraction, visitors can also enjoy other outdoor activities such as boating on the Potomac River, visiting the Smithsonian museums, or exploring the many parks and gardens.

Summer (June-August)

Summer is a popular time to visit Washington, as temperatures are warm and there is plenty of sunshine. However, it can also be hot and humid, especially during July and August. The summer months are a good time to visit the National Mall, see a baseball game at Nationals Park, or take a day trip to nearby beaches or mountains.

Solar Energy Potential

Washington is known for its abundant precipitation, which can overshadow its solar energy potential. However, the state’s eastern regions, particularly the Columbia Basin, receive an average of 5 to 5.5 peak sunlight hours per day, making it a viable location for solar installations. Additionally, the state’s high electricity rates provide a strong economic incentive for businesses and homeowners to adopt solar energy.

Policy and Incentives

Washington has a supportive policy environment for solar energy development. The state’s Renewable Portfolio Standard (RPS) requires utilities to generate a certain percentage of their electricity from renewable sources, including solar. Additionally, the state offers tax incentives, rebates, and net metering programs to encourage solar adoption. These incentives have played a significant role in the growth of solar power in Washington.

Mountains and Ranges:

Washington is renowned for its awe-inspiring mountains and extensive range systems. The dominant feature is the majestic Cascade Range, a volcanic arc stretching north to south along the state’s western border. Iconic peaks like Mount Rainier, Mount St. Helens, and Mount Adams rise high above the landscape, their snow-capped summits visible for miles. The Olympic Mountains, northwest of the Cascades, form a rugged coastal range characterized by lush rainforests and deep glacial valleys. The North Cascades, located in the northern part of the state, boast pristine alpine lakes and towering granite peaks.

Plateaus and Valleys:

In eastern Washington, the landscape transitions into expansive plateaus. The Columbia Plateau, covering most of the region, is a vast lava plain formed by ancient volcanic eruptions. The Okanogan Highlands, in the north-central portion of the state, feature rolling hills, lakes, and river valleys. The Walla Walla Valley, located in the southeastern corner, is a fertile agricultural region renowned for its vineyards and orchards. The Spokane Valley, in the northeast, is a densely populated area framed by the Spokane River and surrounding hills. These plateaus and valleys provide contrasting topography to the mountainous western part of the state.

Seattle-Tacoma International Airport (SEA)

Seattle-Tacoma International Airport (SEA), located approximately 14 miles south of downtown Seattle, is the largest and busiest airport in Washington State. It serves as a major hub for Alaska Airlines, Delta Air Lines, and Southwest Airlines. SEA offers a wide range of domestic and international flights to destinations throughout the United States, Canada, Mexico, Europe, and Asia. The airport has four terminals, with a modern design and amenities such as multiple restaurants, retail stores, and art installations.

Other Major Airports in Washington

In addition to SEA, there are several other major airports in Washington, each serving different regions of the state. Spokane International Airport (GEG) is the second-largest airport in the state and serves the eastern part of Washington, including Spokane and Coeur d’Alene, Idaho. Paine Field (PAE) is located in Everett, north of Seattle, and offers primarily low-cost and regional flights. Yakima Air Terminal (YKM) serves the Yakima Valley region in central Washington, while Grant County International Airport (MWH) in Moses Lake serves the eastern Columbia Basin.

Geography and Climate

Washington, located in the Pacific Northwest of the United States, boasts a diverse landscape that encompasses rugged coastlines, towering mountains, lush rainforests, and serene islands. The Cascade Mountain Range runs north-south through the state, forming a natural divide between western Washington’s temperate climate and eastern Washington’s semi-arid conditions. The western region is characterized by mild temperatures, abundant rainfall, and lush green forests, while the eastern region experiences more extreme temperatures, lower precipitation, and a drier climate.

Culture and History

Washington is a culturally rich state with a diverse population. Seattle, the largest city, is known for its thriving arts and music scene, with institutions like the Seattle Symphony Orchestra and the Seattle Art Museum. The state is also home to a significant Native American population, with numerous tribes maintaining their cultural traditions and heritage. Washington played a pivotal role in the American Civil War, with the Battle of Gettysburg being fought on its shores. The state has a rich history of logging, mining, and agriculture, and today remains a major producer of timber, wheat, and apples.