Excessive heat warning begins Monday, Portland temperatures near 100 likely through Thursday

A woman stands on a pier while a dog jumps into the water

Portland will see temperatures near 100 degrees for much of the week. Oregonian file photo. LC- The Oregonian


Hot, dry air moving westward from east of the Cascades along with a strong high pressure ridge will combine to keep Portland’s high temperatures searing through much of the week.

While daytime highs likely won’t set any records, Portland will see some of the hottest temperatures so far this year, and a fairly long string of them as temps near 100 are likely Monday through at least Thursday.

The National Weather Service has issued an excessive heat warning from noon Monday through 9 p.m. Thursday. Temperatures from 98-103 are possible in the metro area including Portland and Vancouver, and in Washington, Clackamas, Clark and Multnomah counties.

Contributing to the overall heat will be warm overnight temperatures that don’t cool much below 65-70 degrees, offering little relief to those without air conditioning. As of 5 a.m. Monday, most metro locations were seeing temperatures close to 70.

Multnomah County and the City of Portland have issued emergency declarations ahead of this long stretch of high temperatures and are planning to open overnight cooling shelters as soon as Tuesday, in addition to providing other cooling options. Details on cooling shelters had not been released early Monday, but this interactive map shows options as they become available.

Many Multnomah County Library branches will extend hours until 8 p.m. to provide cool places to escape the heat. Check with your local branch.

Another option for some will be heading to the coast. Lincoln City, and other coastal cities will have highs in the low 70s much of the week, with extended cloudy mornings.

Portland will see temperatures around 97 degrees Monday with sunny and clear skies.

Tuesday will be another hot day, perhaps the hottest of the week, with highs likely to reach 101. Some forecast models are showing the possibility of smoke from California wildfires moving up into the region and being dense enough to block some of our solar heating - actually helping temperature stay down a few degrees. Smoke is not expected at the surface, and there’s still some debate on whether it will make it this far north.

Winds will begin to switch more southwesterly beginning Wednesday. This could bring some clouds into the southern portion of the Willamette Valley and a very slight chance of thunderstorms in the central Cascades.

Portland’s temperatures should cool a few degrees from Tuesday’s highs with 98 expected Wednesday.

Extended forecasts are showing continued highs in the upper 90s Thursday, but some possible cooling to the lower 90s by Friday.

For those battling the heat with no electric cooling appliances, Pacific Power shared these energy saving (and house cooling) tips over the weekend:

  • Keep curtains and blinds closed during the day.
  • Open windows, if you can, during cooler evening hours.
  • Operate heat-creating appliances like the clothes dryer and dishwasher at night.
  • Run cooling fans when you’re in the room only. Turn them off when you leave.

Those with air conditioning should:

  • Clean or replace air conditioning air filters.
  • Set units to maintain an interior temperature of 78 degrees to help with energy costs.