Cozy
Cable Knit and Mules
A grey cable knit with fleece-lined leggings and black mules in warmer weather is cozy without capitulating to the temperature. A knit beanie on a warm-clear day feels like a choice.
What to Wear in Seattle in September
September in Seattle is the tail end of the Pacific Northwest's compressed summer — warm, often beautiful, and significantly drier than most of the year, with highs around 70°F and lows near 52°F. About 7 rainy days arrive, increasing toward the end of the month as the rainy season's return becomes unmistakable. Light layers with a packable jacket handle the transition between summer warmth and early fall's cooler evenings.
What to wear
top / Short-Sleeve Top
classic tee
bottom / Jeans
straight-leg
chinos for a slightly smarter look
footwear / Sneakers
classic sneakers
cushioned for all-day city walking
Consider bringing:
Sunglasses
Based on typical September conditions in Seattle. Weather varies year to year — check the live forecast when you're within two weeks of your trip.
September in Seattle marks a delightful transition, bidding farewell to summer's dry warmth and gently ushering in the crispness of autumn. Expect average daytime temperatures to hover comfortably in the mid-60s to low 70s°F (18-22°C), cooling down significantly to the upper 40s to low 50s°F (8-12°C) during evenings and mornings. While the early part of the month can sometimes feel like an extension of August, the likelihood of precipitation steadily increases as September progresses. You won't typically encounter heavy downpours, but rather the characteristic Seattle drizzle or light, intermittent showers. Smart layering is paramount for navigating Seattle's September climate. Start with breathable long-sleeved tops, adding a light sweater, cardigan, or flannel shirt for adaptable warmth. A crucial item is a high-quality waterproof or water-resistant jacket – not necessarily heavy, but effective against persistent mist. Comfortable, closed-toe walking shoes are essential for exploring the city, especially given the increased chance of damp sidewalks. Jeans or versatile trousers are perfect staples, allowing you to move seamlessly from a sunny afternoon stroll to a cool evening out.
Curated Looks
Business Casual
Mauve Happy Hour
At 65–74°F the mauve tie-front cropped linen shirt earns its place over ivory wide-leg linen trousers. Ivory pointed-toe mules and aviator sunglasses make the commute feel like an editorial moment.
Casual
Bright, Blue, and Breezy
Embrace the 65–74°F sunny weather with a breathable linen shirt, classy bermuda shorts, and espadrilles. Pair it with a class bucket bag for that summer ready look.
Chic
White Shirt Wide-Leg
A white oversized button-down with ivory wide-leg linen trousers and a brown woven belt is the warm-clear uniform for someone who doesn't overthink it. Black mule heels are the one decisive choice.
Sporty
Biker Shorts Graphic Tee
A black graphic tee over biker shorts with mule heels is the warm-day sporty look that works from coffee to casual. The olive baseball cap adds a directional touch.
Formal
Ivory and Pleated Maxi
An ivory silk-look blouse tucked into a black pleated maxi skirt is the warm-clear formal look with evening flexibility. Espadrilles and a black mini bag make it daytime without losing the occasion feel.
Cute
Floral Skirt and Mules
A floral pleated midi skirt with a white fitted tank and black mules reads warm-day dressed-up without veering formal. A crochet bucket hat shifts the mood back to weekend.
Packing List
What to Pack for Seattle in September →
Other Months in Seattle
Frequently Asked Questions
What to wear in Seattle in September?+
For Seattle in September, focus on versatile layers. Pack a waterproof or water-resistant jacket, long-sleeved shirts, and a light sweater or cardigan. Comfortable closed-toe walking shoes are also a must, alongside jeans or adaptable trousers, to handle fluctuating temperatures and potential rain.
Is Seattle cold in September?+
Seattle in September isn't typically 'cold' in the freezing sense, but evenings and mornings can be quite cool, often dropping into the upper 40s or low 50s°F. Daytime temperatures are generally mild, ranging from the mid-60s to low 70s°F. Layers are key to staying comfortable throughout the day as temperatures fluctuate.
Does it rain in Seattle in September?+
Yes, the likelihood of rain significantly increases in Seattle during September compared to the drier summer months. While heavy downpours are less common, you should anticipate intermittent light drizzles or showers, especially towards the latter half of the month. A water-resistant outer layer is highly recommended to stay dry.
What should I pack for Seattle in September?+
Pack a good quality waterproof jacket, several long-sleeved shirts, a couple of light sweaters or cardigans, and versatile trousers like jeans. Essential items also include comfortable, closed-toe walking shoes that can handle wet surfaces, and perhaps a small, compact umbrella for unexpected drizzles.
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