Weather in Seattle

Planning your day in Seattle? Here you will find the latest weather information, including detailed forecasts and visual charts, to make your stay in the city as comfortable as possible.

Seattle welcomes guests with a moderate marine climate, characterised by mild temperature fluctuations throughout the year. There are four distinct seasons: winters here are quite damp and cool, but without severe frosts, while summers are generally warm and sunny. Spring and autumn offer pleasant freshness and changeable weather, making the city attractive to visit at various times.

A key feature of Seattle's climate is the distribution of rainfall. The highest amount, along with overcast days, occurs from late autumn to early spring, especially from November to February, when the number of rainy days reaches 19-21 per month. However, the summer months, particularly July and August, will delight you with plenty of sunshine and minimal rain (only 5-7 rainy days), creating ideal conditions for walks and exploring the city and its surroundings.

The temperature regime in Seattle is characterised by moderation throughout the year. The hottest month is usually August, when the average temperature reaches 20.2°C, and daytime highs can rise to 25.1°C. It is slightly cooler in July with an average temperature of 19.8°C. The coldest month is considered to be February, with an average temperature of 5.1°C and minimum night-time values around 2.5°C, although January and December are also quite cool, with average temperatures around 6.0°C and 5.6°C respectively.

The summer months in Seattle, from June to August, offer residents and visitors pleasantly warm weather. Daytime temperatures in July and August most often fluctuate in the range of 20-25°C, creating comfortable conditions for outdoor activities. Nights bring refreshing coolness, as the temperature drops to an average of 12-15°C. Such daily fluctuations, where the difference between day and night temperatures can be about 8-10°C, are a characteristic feature of the summer period in Seattle.

Winter in Seattle, covering the period from December to February, is distinguished by mildness and coolness. Average daytime temperatures stay within 7-8°C, and night-time temperatures drop to 2-4°C. Severe frosts are rare here. Daily temperature fluctuations in winter are less pronounced than in summer, amounting to approximately 4-5°C. The transitional seasons, spring and autumn, are characterised by gradual temperature changes: in spring the air warms up from an average of +7.3°C in March to +13.7°C in May, and in autumn it cools down from +17.2°C in September to +7.8°C in November.

Seattle is known for its changeable weather, and precipitation plays a key role in this, clearly dividing the year into wet and dry seasons. The highest amount of precipitation falls from late autumn to early spring. January is the wettest month, when an average of 7 mm of precipitation falls, and the number of rainy days reaches 21. A similar picture is observed in November and December, each of which brings about 6 mm of precipitation and approximately 19 rainy days. The character of winter precipitation in Seattle is most often prolonged but not heavy rain or drizzle, which creates the city's reputation as "rainy".

The summer period, conversely, gives Seattle significant relief from the rain. The driest months are July and August, when precipitation is minimal – just 1 mm each, and the number of rainy days drops to 5-7. This makes summer the most favourable time for visiting the city and active recreation. Transitional months, such as May, June, and September, are also characterised by a relatively small amount of precipitation (about 2 mm) and a moderate number of rainy days (10-12), offering comfortable conditions before the onset of the wetter or drier season. October already heralds the arrival of the wet season with 4 mm of precipitation and 16 rainy days.

When packing for Seattle, it is worth remembering its famous changeable weather and high humidity, especially from autumn to spring. The key principle when packing your suitcase should be layering. Regardless of the season, a waterproof windbreaker or a light jacket with a hood will become your best friend. Be sure to take an umbrella with you – it will come in handy in any month, but will be especially relevant in the period from October to April, when the number of rainy days is at its maximum. Comfortable waterproof shoes are also extremely important for comfortable walks around the city, especially during the rainy seasons.

In the cold season, from November to March, when average temperatures fluctuate between 5°C and 7°C, pack warm sweaters, fleece tops, a hat, gloves, and a scarf. Jeans or thick trousers will be appropriate. In summer, especially in July and August, when the average temperature rises to 20°C and above, and the number of rainy days is minimal, you will need t-shirts, shorts, light trousers, or dresses. However, even in the warmest months, evenings can be cool, so a light cardigan or hoodie will not go amiss. Don't forget sunscreen and sunglasses for clear summer days.

In the off-season (April-May and September-October), the weather can be particularly unpredictable. The sun may shine during the day, but by evening it may rain and get colder. Therefore, layered clothing – a sweater or fleece that can be taken off or worn under a jacket – will be the optimal solution. In general, Seattle is characterised by moderate temperatures without extreme heat or cold, but readiness for rain and wind is the guarantee of a comfortable trip at any time of the year.