Search results
Jul 18, 2022 · The weather in Seattle in September is beautiful. Temperatures stay in the 50s, and high 60s throughout the month, sometimes pushing into the low 70s. You’ll be able to wander downtown without getting poured on, experience warmth from the sunshine, and enjoy all the outdoor activities you want.
- Caitlin Lloyd
Get the monthly weather forecast for Seattle, WA, including daily high/low, historical averages, to help you plan ahead.
Feb 14, 2024 · In Seattle, the average seawater temperature in September is 53.2°F (11.8°C). Note: Dipping into 53.2°F (11.8°C) below 50°F (10°C) needs protective wear, or you'd face cold shock and breathing issues swiftly. Meanwhile, a slight swim around 55.4°F (13°C) feels cold to the bone.
- September temperatures in Seattle vary between a high-temperature of 69.6°F and a low-temperature of 50.5°F .
- The average relative humidity in September is 75% .
- In Seattle, Washington, during September, the rain falls for 6 days and regularly aggregates up to 0.28" of precipitation .
- April through October and December are months without snowfall .
- In Seattle, in September, the average water temperature is 53.2°F . Swimming in 53.2°F is considered dangerous. Unprotected immersion in temperatur...
- In Seattle, Washington, the average day length in September is 12h and 33min .
- In September, on the first day of the month, sunrise is at 6:28 am and sunset at 7:50 pm . On the last day of the month, sunrise is at 7:07 am and...
- The average sunshine duration in September in Seattle, Washington, is 9.4h .
- The average daily maximum UV index in September in Seattle is 4 . A UV Index estimate of 3 to 5 represents a moderate vulnerability from unsafe exp...
In Seattle the weather in September is generally perfect, characterized by pleasant temperatures and moderate rainfall. September is a summer month. Anticipate daytime temperatures around 22°C , while night temperatures can drop to 12°C .
September marks the transition to fall in Seattle, with mild temperatures. Average temperatures range from 52°F to 70°F (11°C to 21°C). Days begin to shorten, with around 13 hours of daylight, and rain showers become more frequent. September receives an average of 1.5 inches (38 mm) of precipitation.
September Weather in Seattle Washington, United States. Daily high temperatures decrease by 8°F, from 75°F to 67°F, rarely falling below 59°F or exceeding 83°F. Daily low temperatures decrease by 5°F, from 57°F to 51°F, rarely falling below 45°F or exceeding 61°F.
Nearly every September day warms to over 60 degrees Fahrenheit (16 degrees Celsius) in Seattle. The city averages 4 days this month when the thermometer reaches into the 80s °F (over 27 °C). Temperatures above 90 °F (32 °C) are unusual here during September.
