Boulder shatters heat record for the date

Temperature of 99 degrees passes 2021 marker of 94

Just after 3 p.m. Friday, Boulder shattered the heat record set Sept. 10, 2012, according to the National Weather Service Boulder, which officially recorded the mercury at 99 degrees Fahrenheit.

“The prior record heat in Boulder was set in 2012 at 94 degrees,” NWS Boulder meteorologist Ayesha Wilkinson said.

Boulder meteorologist Matt Kelsch confirmed Friday’s 99-degree record, noting, “That is the hottest it has ever been this late in the season, going back to 1897.”

Neighboring city Longmont didn’t break its heat record of 96 degrees set in 1979, Wilkinson said, although the mercury hit 93 Friday.

“Neither Boulder nor Longmont have broken prior records of above- 90-degree days this summer yet,” Wilkinson noted.

Since June 1 through Friday, Boulder has seen 45 days above 90 degrees, and Longmont has seen 53 days above 90 degrees.

However, Wilkinson said there is some relief in sight for both Boulder and Longmont because “a little bit of moisture is coming in this weekend through Monday with isolated thunderstorms, which will bring both areas down to the low to mid-80s.”

“By Tuesday both areas will be back to drier conditions but with temperatures still in the low to mid-80s,” Wilkinson added.

August saw 16 days above 90 degrees in Boulder, the highest number of days for 2021, and only three days have been over 90 in September.

Longmont recorded 18 days above 90 degrees in July, and five days were over 90 in September so far.