Seattle wraps up second-hottest, second-driest meteorological summer on record
SEATTLE -- Happy first day of autumn! Well, at least on the meteorological calendar. While the autumnal equinox is still three weeks away, meteorologists measure summer from June 1-Aug. 31 for statistical purposes.
And if it seemed like once again, it was a pretty hot and dry summer, you would be right, with several records either toppled or neared -- and that was with a rather tame June factored in!
In Seattle, it will go down as the second-hottest meteorological summer on record at Sea-Tac Airport by average high temperature, coming in at 77.9 degrees. The only hotter summer was the scorcher of 2015, which had an average high of 80.2 degrees.
By month, June's average high was 71.9 -- only 25th warmest as it was fairly close to normal. But July was the hottest on record at 82.8 degrees. August wasn't too far behind at 79.1 degrees, good for 8th warmest on record. August's numbers would have been higher had it not been for the several days of smoky skies during our hot spells that shaved 4-8 degrees off our highs.
That smoke was a reflection of the dry summer as well, which gets recorded as the second-driest on record at 0.88 inches of rain from June through August. The driest summer was 1987 at 0.84 inches.
It was consistency that got us to runner-up status, as none of the individual months placed in the Top 5 driest. The bulk of the rain came in June at 0.63", tied for 14th driest. July only managed 0.05" but it was wetter than five other Julys. And August came in with 0.20" -- good for 13th driest. But it marked the third year in a row we received less than a quarter inch of rain in August. Sure, summers are usually quite dry around the Northwest but add up July and August's 2017 and 2018s together and those four months totaled 0.27". Some thunderstorms in Florida drop that in minutes.
Other heat stats: 20 days at 80 degrees or more in July was the second-most (record: 21). But 16 days at 85 or warmer was a record for July (beating the old record of 12). 9 days at 85+ in August was tied for 4th-most; the record is 16.
Overall, Seattle has had 43 days at 80 degrees or warmer this year (including some 80s in spring) which is currently 7th most. Hitting 80 is September is not out of the question so this has some potential to keep climbing the ladder - though long-range models currently don't indicate any 80s in the first several days of the month.
The big record to fall was is the 31 days of 85+ degree heat, shattering the old record of 27 set...last year. The normal is 10.
And even 90s were common, with 11 days at 90 or hotter, just missing the record of 12 set in 2015. The smoke probably thwarted setting this record as we had some days that the raw computer forecast calculations had forecasted at 90 or hotter but the smoke kept Seattle in the 80s. Although Seattle didn't have any days at 95 or hotter, surprisingly. Our hottest day of the year so far is 94.
Long range climate models are still leaning toward a warmer and drier than usual autumn and winter, thanks in part to an expected El Nino.