September record dry month
October 12, 2022
The 0.02 inch of rain that fell Sept. 2 was the month's total precipitation and really a rain for the record. How dry was it? While five years this century have had less than one inch of rain, this was the only time less than one-tenth of an inch fell.
Average September rainfall for this century has been pushed down to 1.9 inches. Fourteen years there has been less than 2 inches of rain, including 2016-2018 when between 1.3 and 1.6 inches fell.
It rained 14 days in 2021. Last year's 3.2 inches was a very different story, one of four years over 3 inches come down. The 5.2 inches in 2019 is the century's record rainfall.
It was warm, too, with the daily average high of 71.9 degrees 3.8 degrees above the century daily average high temperature. The 59 degree average temperature was 0.8 degrees above the century average. The 77.1 degree high Sept. 26 was not the hottest day of the month but was a record high for that day.
The month started warm, with the average temperature Sept. 1-4 between 61.3 and 62.9 degrees. The month's high of 80.7 degree Sept. 11 provided the month's highest daily average temperature of 63.4 degrees.
Three daily low temperature records were set, Sept. 16-19 at 38.3, 37.2 and 37.6 degrees, respectively, the only mornings below 40 degrees. They pushed the average daily minimum down to 47.5, 1.4 degree below the century's average daily low.
Record lows in 2021 were Sept. 1-2 of 49.9 and 40.8 degrees and 39 degrees Sept. 16. Sept. 9 last year was a record high of 80.5 record high.
The 16.6 inches of rain in 2022 is 3.9 inches under the century average of 20.5 inches, 19% less. Six months, including July-September, have had less than average rainfall. Only June's deluge brought the year's rain above 15 inches.
Measurements and data are at Washington State University's Mount Vernon weather station on Memorial Highway.