The temperature keeps rising in the Tri-Cities this week, possibly peaking at 88 degrees Wednesday.
That would be about 20 degrees above normal for the third week of April.
Tuesday was almost as warm, with temperatures reaching 86 degrees by late afternoon in Richland, according to the National Weather Service.
The high pressure system should remain over the Mid-Columbia through Thursday.
Then a series of weather systems is expected to move over the region, bringing cooler temperatures and a slight chance of showers.
Highs should gradually drop to the high 60s by Sunday, according to the weather service.