PORTLAND, Ore. (KOIN) — Portland is working with one of the warmest Septembers on record and we will keep it going Monday afternoon as temperatures once again push the upper 80s.

High pressure keeps conditions warm, dry and clear in the Willamette Valley. We only will have a few hours in the upper 80s before those temperatures cool down as the daylight wraps up earlier than peak summer months.

There will be some areas of patchy fog for the Oregon coast Monday morning. That will likely be more of a central Oregon coast pest. Daytime highs around 70 degrees coming out of Tillamook. We have a few dry days even for the coast to start the week.

Right now we have just about perfect outdoor weather for hikes and sporting events. You can grab a hike up near Trillium Lake with temperatures in the 70s!

A stronger marine influence will arrive on Tuesday, providing cooler air for the Oregon coast. There will also be a line of clouds for the coast on Tuesday. That marine layer will move in for the Willamette Valley on Wednesday.

Swipe through the slideshow below to see the forecast in your area.