Going back further, you can find 100 degrees in mid July of 1941: https://www.currentresults.com/Yearly-Weather/USA/WA/Seattle/extreme-annual-seattle-high-tempe

Going back further, you can find 100 degrees in mid July of 1941: https://www.currentresults.com/Yearly-Weather/USA/WA/Seattle/extreme-annual-seattle-high-temperature.php https://www.currentresults.com/Yearly-Weather/USA/WA/Seattle... Though, that was before Sea-Tac was the official weather station: https://www.king5.com/article/news/local/seattle/heres-why-seattles-weather-records-are-taken-at-seatac-airport/281-d587a9bd-a4b6-4915-8856-12b8b2e2618f https://www.king5.com/article/news/local/seattle/heres-why-s...