We’re choking on smoke, and the hottest days are coming for Tri-Cities

The hottest days of the Tri-Cities’ summer are forecast for this week, with smoke hanging around too.

The temperatures for most of the Mid-Columbia will peak at 107 to 111 degrees, said Zaaron Allen, a meteorologist for the National Weather Service.

The weather service predicts a high of 108 on Wednesday and 109 on Thursday at the Tri-Cities Airport. It has issued an excessive heat warning.

Temperatures won’t cool down enough to give much relief at night, Allen said.

Most nights will be 70 or warmer, with cooling into the 60s only briefly around dawn, Allen said.

On Monday, the smoke was coming from fires to the west, including the Miriam fire near White Pass in the Cascade Mountains and the South Valley fire burning south of the The Dalles in Oregon.

Later in the week, the winds are expected to shift, bringing smoke to the Tri-Cities from fires burning in Southwest Oregon and Northern California.

The Benton Clean Air Agency reported Monday morning that air quality that had deteriorated to a level unhealthy for certain sensitive groups. Air quality improved some in the afternoon.

Children, the elderly, pregnant women and people with chronic health conditions such as asthma or diabetes should limit their time outdoors when air quality is rated “unhealthy for sensitive groups,” according to the Washington departments of Health and Ecology.

But the bigger risk to health this week likely will be the heat, Allen said.

Any outdoor activities should be planned for the coolest hours of the days, he said. Workers who have to be outside should take frequent breaks and drink plenty of water.

Cooler weather is coming later in the week, or at least relatively cooler weather.

“We’ll go from excessively hot to seasonably hot,” Allen said.

Ocean air should push into the area starting Friday, bringing the highs in the Tri-Cities down to the low 90s for the weekend, according to early forecasts.

Today and Tuesday the high should be around 100 in the Tri-Cities.

Humidity has been even lower than usual this summer in the Mid-Columbia.

A measurement of just 5 percent humidity was recorded on July 17 at the Hanford Meteorology Station, an all-time record low for the station. It has daily records back to the mid-1940s.

It also reported that the average humidity for the month was 25.7 percent, the fifth lowest on record for July.

Low humidity increases the risk that wild fires will spread.

This story was originally published August 6, 2018 at 12:01 PM.