seattle humidity average

Seattle Humidity: What’s the Average?

Seattle, often associated with rain, actually has a surprisingly moderate humidity level. The average relative humidity in Seattle typically ranges from around 60% in the afternoon to 80% in the morning, contributing to its reputation for dampness.

Understanding Seattle’s Humidity

While Seattle is known for frequent rainfall, its humidity is primarily influenced by its proximity to the Pacific Ocean. The ocean’s moisture contributes to consistent humidity levels, although rarely reaching the extreme levels seen in more tropical climates. It’s important to distinguish between relative humidity and absolute humidity. Relative humidity, the percentage you often see reported, refers to the amount of moisture in the air compared to the maximum amount the air could hold at that temperature. Seattle’s moderate temperatures contribute to its moderate relative humidity.

Seasonal Variations in Humidity

Like many places, Seattle experiences seasonal variations in humidity. The summer months (July and August) tend to be the driest, with humidity slightly lower than the rest of the year. This is due to warmer temperatures and less frequent rainfall. During the fall, winter, and spring, humidity tends to be higher because of increased precipitation and cooler temperatures. However, even during the wetter months, Seattle’s humidity rarely reaches uncomfortable extremes.

Factors Affecting Humidity Levels

Several factors contribute to Seattle’s humidity levels. The Puget Sound, a large body of saltwater, plays a significant role in regulating the regional climate and providing a constant source of moisture. Weather patterns from the Pacific Ocean also bring moist air inland. Finally, the Olympic and Cascade mountain ranges trap moisture, contributing to Seattle’s overall dampness.

How Seattle’s Humidity Compares

Compared to other cities, Seattle’s humidity is moderate. It’s significantly lower than cities in the southeastern United States, known for their high heat and humidity. It’s also typically lower than cities in the Midwest during the summer months. To learn more about average humidity levels across various locations, you can refer to reliable sources like Wikipedia’s page on Humidity.

Frequently Asked Questions About Seattle Humidity

Is Seattle humid or dry?

Seattle is considered moderately humid. It’s not as dry as desert regions but not as humid as tropical areas.

Does Seattle feel humid?

Due to the cool temperatures, Seattle’s humidity can often make it feel cooler and damper than the actual temperature suggests.

What is the most humid month in Seattle?

While humidity levels are relatively consistent, the fall and winter months tend to have slightly higher humidity due to increased rainfall.

Does humidity affect rainfall in Seattle?

Yes, higher humidity contributes to increased cloud formation and a greater likelihood of precipitation.

How does humidity impact comfort in Seattle?

High humidity can make the air feel heavy and clammy. In Seattle, this usually translates to a damp and cool feeling, especially during colder months.

Summary

Seattle’s average humidity, ranging from 60% to 80%, contributes to its reputation for a damp climate. While the city isn’t excessively humid, its proximity to the Pacific Ocean and consistent rainfall result in moderate levels of moisture in the air. This humidity, combined with cooler temperatures, often makes the city feel damper than the actual temperature reading suggests.