Weather By Day

September Weather In Seattle  
September Seattle Weather
Record High: 92°F
Normal High: 70°F
Normal Low: 52°F
Record Low: 40°F
Avg Monthly Rain: 1.63"
Rec 1 Day Rain: 1.7"

Seattle Weather In September

In the last 66 years the highest measured September temperature in Seattle was 92 degrees Fahrenheit, most recently encountered on September 28, 1967, while the mean high temperature is 70. The lowest measured temperature in Seattle for the last 66 years in September was 40 registered on September 27, 1972, and the average low daily temperature is 52.

National Weather Service historical Seattle September Weather data indicates that on September 24, 1972, the recorded high did not exceed 49 degrees Fahrenheit, the lowest high measured in Seattle in the past 66 years. NWS weather data additionally shows that on September 3, 1949, the lowest recorded temperature on that day did not drop below 64 degrees, the highest low measured in Seattle in the last 66 years.

According to the National Weather Service, the high temperature in Seattle in September on the first day of the month averages 72 degrees and the high on the last day of the month averages 66 degrees. The average recorded low temperature in Seattle on September First is 56 degrees Fahrenheit and the average low on the last day of September is 52 degrees.

Seattle normally receives an average of 1.63 inches of rain during September. The most precipitation recorded on a single day in September, according to September Seattle Weather data, was 1.7 inches on September 30, 1953.