Region’s year of record-breaking weather continues with coldest early-October day in 125 years
Seattle’s year of record-breaking weather has marched on in the first two weeks of October, with the region now experiencing some of its coldest early-fall days in over 125 years.
According to the National Weather Service, Tuesday’s average temperature of 43 degrees marked the coldest day Seattle has ever seen in the first two weeks of October, with a high of 50 degrees and a low of 36 degrees. The previous record was 43.5 degrees (high of 54 degrees and low of 33 degrees) set on Oct. 14, 1899.
When Seattle hit 36 degrees early Tuesday morning, that was also the first new record low in October in nearly two decades.
This marks the latest in a series of extreme weather events in the Puget Sound region in 2021.
On Feb. 13, 8.9 inches of snow fell in the Seattle area. That was the snowiest day the city had seen in any month in 52 years, and the most it had seen on a February day in nearly a century. Combined between Feb. 12 and Feb. 13, that was also the most snow the Seattle area had seen over a two-day period in 49 years.
Then in early June, widespread thunderstorms drenched the Puget Sound region, with 0.68 inches falling on a single day at Sea-Tac (where the NWS measures rainfall in the Seattle area). That topped a 75-year-old record for June 13.
Three weeks later, an historic heat wave shattered records across Western Washington, with scorching high temperatures everywhere from Bellingham down to Olympia. Areas in Washington that broke all-time records for their hottest ever days during that period included:
- Seattle (Sea-Tac) 108 degrees, previously 104 on June 27, 2021
- Bellingham 99 degrees, previously 96 on July 29, 2009
- NWS Seattle 107 degrees, previously 105 on July 29, 2009
- Olympia 110 degrees, previously 105 on June 27, 2021
- Quillayute 110, previously 99 on Aug. 9, 1981
In late July, dry conditions across the state then had Washington experiencing an all-time record for fires that burned over 375 square miles in less than two months. That was twice what burned across all of 2019, and “almost double the 10-year average” for that period of the summer, according to Washington Commissioner of Public Lands Hilary Franz.
In Okanogan County, people also grappled with the worst air quality they had experienced in July in 15 years of available data. In Winthrop, residents were sandwiched between a pair of large fires to its eastern and western edges, at one point experiencing the worst measured air quality on the entire planet.
Those conditions extended into early August, with the Seattle area experiencing a streak of 51 straight days without any measurable rainfall. That marked the second longest streak for Sea-Tac, bested only by a run of 55 straight rain-free days in 2017.
A month later, the region had then shifted into extreme wet weather conditions, with 0.81 inches of rain falling on Sept. 18. That broke an 11-year-old record for the day. Over that weekend, Seattle experienced 86% of its total average September rainfall in just three days.