Seattle area’s ‘insane’ heat wave finally gives way to cooler weather

The sun is shining near the Space Needle, Monday, June 28, 2021. (AP Photo / Ted S. Warren)

Temperatures in the Puget Sound region have already begun to cool off after a record-breaking heatwave covered the past three days.

The Seattle area hit triple digits on Monday for the third straight year, hitting 108 degrees, officially making it the hottest day in Seattle in its history. Before this last week, the city had never seen consecutive 100-degree days.

The big cooldown

An excessive heat warning will stay in place through Tuesday evening, but forecasters have said Tuesday will be about 20 degrees cooler even over Puget Sound.

👀 Can you see the naval thrust? The ocean layer has started to move inland tonight, cooling the areas along the coast and in the southwest of the country by 30 degrees in some places. #wawx pic.twitter.com/UdFYSkttqc

– NWS Seattle (@NWSSeattle) June 29, 2021

According to the NWS, the cooler sea air moves north from the coast. In fact, Westport fell from 83 to 64 late Monday morning. Shelton rose from 106 degrees at 7 p.m. to 75 at 9:30 p.m.

In the Seattle area, nighttime temperatures finally plummeted into the 60s after sitting at a hot 80 degrees on Sunday night. On Tuesday morning the temperatures were between 10 and 25 degrees cooler than the day before at the same time.

The temps remain about 10-25 degrees cooler this morning than yesterday at this time. Thanks to the natural air conditioning in the west of WA … the marine push! In some places it is only 5 to 10 degrees cooler today … but there is good news … tonight another sea foray is moving inland! #wawx pic.twitter.com/CHktAkDq91

– NWS Seattle (@NWSSeattle) June 29, 2021

While temperatures are expected to end in the low 90s on Tuesday, the NWS extended the excessive heat warning to Tuesday night due to the recovery period.

“It is imperative that heat-related precautionary measures are not automatically neglected,” wrote the NWS in its forecast discussion. “The heat-related effects are likely to continue as there won’t be an extended period of cooler temperatures to fully recover from the extreme heat of the past few days.”

According to the NWS, Wednesday will bring more cooling. Interiors will see highs in the mid-1980s. Areas near water and at high altitude should remain in the upper 60s and lower 70s. There will be similar patterns on Thursday.

Records and stuff

Temperatures in Seattle reached 100 degrees just before 4 p.m. on Saturday and 104 degrees again just after 2 p.m. on Sunday, setting the city’s all-time record for the hottest day ever. Monday broke this record at 108 degrees around 6 p.m.

Other areas broke all-time records on Monday (according to the National Weather Service):

• Dallesport 118 degrees
• 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 109 degrees, previously 105 on June 27, 2021
• Quillayute 110, previously 99 on August 9, 1981

The record high of 110 ° F at Quillayute not only narrowly broke the previous high, but exceeded the previous high by 11 degrees! Just as remarkable was yesterday’s record in Hoquiam, which set a new mark by 8 degrees! (Map via @ Climatologist49) pic.twitter.com/Oi1NG3iHLf

– NWS Seattle (@NWSSeattle) June 29, 2021

The NWS also noted on Monday that Dallesport’s high of 118 was “tentative”. If certified, it would set the record for the hottest day in Washington history.

All in all, it marks a time that Cliff Mass of the University of Washington described as “just crazy” as the region went through a period of “unprecedented heights”.