1st Tri-Cities heat wave of 2025 coming. Will 100+ temperatures break records?

The heat is coming early to the Tri-Cities this year.

The National Weather Service forecasts the first triple digit temperatures of the year on Sunday as the Pacific Northwest swelters under a heat wave.

A high pressure system will be trapping heat, with temperatures starting to build late this week in the Tri-Cities.

Cole Evans, a weather service meteorologist, compares the high pressure system to a car, that heats up inside in the summer with no way for the heat to escape.

Tri-Cities highs should be in the 80s through Thursday, reaching 84 on Friday and 98 on Saturday.

Sunday and Monday the highs should top 100 degrees at 102, according to the weather service.

Highs on those days usually average about 80 to 82 degrees, making the coming heat wave about 20 degrees warmer than usual.

Highs should come close to temperature records.

The daily Tri-Cities high record for June 8, which is Sunday this year, is 105 degrees set in 2015, and the record high for June 9 is 104 degrees set in 1918.

Temperatures will cool some starting Tuesday, when a Tri-Cities high of 97 is forecast.

Unfortunately for those seeking relief from the heat, Tri-Cities public swimming pools are not open yet.

The Richland, Kennewick and Pasco pools will open Saturday, June 14.

However, splash pads across the two cities are already open.

And there’s always the Columbia River. River water will still be cool this time of year, but will have warmed some from the cold temperatures that prompted hypothermia warnings a month ago.

Relative humidity in the Tri-Cities will fall at least into the teens and possibly the single digits as temperatures rise, Evans said.

Wildfires are always a risk during hot weather in the greater Tri-Cities area.

But the wind, a primary risk for wildfires, should be light in the coming days. In addition, vegetation from a mild, wet spring has yet to dry out.

This story was originally published June 4, 2025 at 12:39 PM.