RIVERSIDE, Calif. -

A spell of unseasonably high temperatures in Riverside County will end today before a cooling trend sets in for the rest of the week, meteorologists said.

The heat wave that began last weekend is being caused by a ridge of high pressure over the region, according to the National Weather Service.

Several record-high temperatures were recorded around the county Monday, including 105 degrees in Elsinore. The previous record high for May 13 in Elsinore was 104 degrees, set in 1927.    

Highs today were expected to be in the 90s in the valleys, high 80s to high 90s in the mountains and 105 to 110 degrees in the Coachella Valley.