The climate of Seattle
, is designated under the Köppen climate classification as Csb, which signifies a Mediterranean climate with warm summers. The city's location has a notable influence on the variation in weather parameters throughout the year. Average high temperatures over the year range from 43.7°F in December
to 76.3°F in August
. Meanwhile, average low temperatures fluctuate from 35.1°F in December to 54°F in August.
The percentage of relative humidity in Seattle also differs considerably over the year, starting from 69% in July
and reaching a peak of 85% in January
. Furthermore, rainfall observes a contrasting pattern, with the minimal amount occurring in July and August 0.12", while the maximum precipitation of 0.87" happens in December. Remarkably, despite being in a region known for its rainfall, the city observes just under nine days of rainfall on average per month, with the highest frequency in November
at 9.1 days and the lowest in August at 2.8 days.
In terms of sunshine, Seattle receives 10.7 hours per day on average during August, in contrast to December when daylight hours reduce to a mere 8.5 hours per day. On the other hand, wind speeds in Seattle vary marginally, clocking a high of 5.3mph in March
and a low of 3.5mph between July and August.
The best time to visit Seattle
's climatological data suggests that the months from May
offer the most conducive conditions for tourists. During this period, the city experiences moderate temperatures ranging from 56.5°F to 76.3°F. The humidity levels are also lower, between 73% and 75%. Moreover, these months record the least amount of rainfall, with August
recording a minimal 0.12", while the rainfall days are also at their lowest throughout the year. Also, Seattle experiences the highest levels of sunshine, between 9.2 hours and 10.7 hours daily, which is ideal for outdoor activities and sightseeing.
The worst time to visit Seattle
The months between November
are generally less desirable for tourists due to the prevailing weather conditions. During these months, temperatures drop to average lows between 35.1°F to 36°F and highs do not exceed an average of 50.5°F. These months also witness greater precipitation, with average rainfall quantities between 0.59" and 0.87", and the frequency of rainy days also increases. Moreover, daylight hours are at their lowest, adversely affecting tourism activities.
Spring weather in Seattle
Spring in Seattle
, between March
, witnesses a gradual increase in temperatures from an average high of 50.5°F in March to 64.8°F in May. This period also sees a decrease in average humidity from 82% to 75%. Rainfall continues to diminish, recording 0.35" in March down to 0.39" in May. Days gradually become longer with daylight hours ranging from 11.9 hours in March to 15.2 hours in May, allowing more opportunities for outdoor activities.
Summer weather in Seattle
Summer, from June
, is the warmest period in Seattle
with average high temperatures rising from 69.1°F to 76.3°F. Relative humidity is at its lowest during these months, between 69% and 73%. Rainfall reaches its yearly minimum in July
and August, reporting a mere 0.12", making summer the driest season in Seattle. Despite the overall dry conditions, the city is in full bloom and this is considered an ideal time for tourists.
Autumn weather in Seattle
Autumn, from September
, experiences a decrease in temperatures with an average high curving from 69.6°F in September to 49.1°F in November. There is a marked upward shift in humidity from 75% to 84%. Rainfall levels start increasing in this period, with November documenting 0.63". Despite the increased rainfall, this season paints a vibrant hue across the city making it attractive for visitors.
Winter weather in Seattle
Winter in Seattle
, spanning December
, is the coldest period with average high temperatures within 43.7°F and 46.2°F, and average lows hovering between 35.1°F and 36°F. The relative humidity remains fairly high during these months at 84% to 85%. These months also see an escalation in precipitation, with December attaining the maximum average rainfall of 0.87". Despite having reduced daylight, this season has its own charm, offering a unique winter experience for visitors.
Weather in January
Winter still holds Seattle
in its firm grip as the year takes off, though the climate is milder than some other states. This month, temperatures fluctuate between 36°F and 45°F, making it relatively mild for a winter month. Outdoor elements characteristic of winter can be expected, including rainfall and occasional snowfall. Weather in January »
Weather in February
sees a subtle shift in weather, with temperatures incrementally rising compared to January
. It brings a slight increase in sunshine hours and a decrease in both rainfall and snowfall. The weather remains comfortably cool, as it has not yet transitioned fully to spring conditions. Weather in February »
Weather in March
heralds the beginning of spring in Seattle
, bringing an aura of freshness and rejuvenation. The shift from winter to spring is subtle - more noticeable in the blooming flora than in the slow rise of temperatures. Still, conditions are a step warmer than February
, showing a slight increase in average daily sunshine. Weather in March »
Weather in April
’s warmer temperatures and lower humidity make it a pleasant time for outdoor activities in Seattle
. Temperatures typically begin to show a consistent rise, signaling a move away from the winter chill. The reduction in cloud cover accompanying the change in seasons often creates breathtaking sunrise and sunset views from the city’s many vantage points. Weather in April »
Weather in May
, often dubbed "Seattle
's secret summer," offers increasingly pleasant weather. There is an increase in daytime temperatures, and the humidity decreases, making conditions ideal for exploring the city’s attractive landscapes and vistas. Weather in May »
Weather in June
ushers in summer in Seattle
, with temperatures climbing to the year's warm levels. Sea temperatures begin to rise, tempting beachgoers to the city's inviting shores for some fun in the sun. It is an eventful time, with locals outdoors enjoying the extended daylight and appreciable amount of sunshine. Weather in June »
Weather in July
stands out as the hottest month in Seattle
, with temperatures reaching an average high of 75.9°F. Clear skies, along with extended daylight, mean that sunshine is abundant. Low rainfall characterizes this month, making it an ideal period for outdoor activities. Weather in July »
Weather in August
maintains the summer heat, with temperatures nearly mirroring July
's highs. Rain becomes even more scarce, and the city revels in clear, sun-drenched days. As the warmest sea temperatures take hold, August asserts itself as an excellent time for swim enthusiasts to take a dip in the calm waters. Weather in August »
Weather in September
marks the transition from summer to fall, with a gradual drop in temperature. Days begin to shorten and temperatures start to cool off after the summer’s heat, but the city continues to enjoy fairly sunny and dry conditions. Weather in September »
Weather in October
is characterized by cooler temperatures as Seattle
enters the heart of the fall season. Rain returns in slightly greater quantity, but warm and sunny days are still quite typical. This month brings a spectacular display of fall foliage, as leaves turn into vibrant shades of red, orange, and gold. Weather in October »
Weather in November
escorts in the cooler late-autumn weather in Seattle
, with a noticeable decrease in temperatures. It marks the transition from fall to winter, with cooler temperatures and a substantial increase in rainfall. Prevailing winds are moderately light, but gusts can occasionally reach up to 8.6mph. Weather in November »
Weather in December
introduces the winter season in Seattle
, bringing colder temperatures and increased cloud cover. With the average lows dipping to 35.1°F, it is the coolest month on the calendar. This period experiences the shortest daylight hours due to the winter solstice, adding to the wintry ambiance. Weather in December »