PORTLAND, Ore. (KOIN) – Much of the Willamette Valley along the I-5 corridor is expected to break temperature records on Friday as this year’s historically cold and rainy April shifts toward drier, sunnier weather.

The National Weather Service predicts at least an 80 to 90% chance of Friday’s high rising above 80 degrees. If temperatures exceed 82 degrees on Friday, Portland will break its daily high record of 82 degrees set in 1998.

Portland’s weekly forecast. (NWS)

Following the anticipated spike, KOIN 6 Meteorologist Kelley Bayern reports that temperatures could cool dramatically by early next week.

“We continue with the dry weather and warming trend as we hit the mid-80s on Friday, likely a record breaking day of heat,” Bayern said. “There’s a chance for light spotty showers returning on Sunday or Monday, but certainty is low on that at the moment.”

Although temperatures may seem ideal for swimming, the National Weather Service warns that local lakes and rivers are still much too cold for recreational swimming.

“As things warm up, we know many will want to head to local rivers and lakes,” the NWS stated. “Remember that rivers are very cold still with temperatures in the 40s. Cold water shock is very real, and cold water is very deadly. Don’t become a statistic this week.”