Portland woke up Saturday to clear skies and crisp air, with temperatures near 57°F at Portland International Airport. That calm, cool start will not last long, though, as inland areas are headed for a quick warm-up: sunny afternoons are expected through the weekend, with highs climbing into the 80s today and a more pronounced heat spike settling in early next week.
Afternoon Heat Builds Inland
Interior valleys are expected to reach the low to mid 80s on Saturday and climb into the upper 80s on Sunday, with highs near 90°F on Monday, July 20 and around 93°F on Tuesday and Wednesday. Forecasters note there is a 20-50% chance that some of the historically warmer valleys could slip into the mid 90s, raising the risk of cumulative heat impacts for people without effective cooling. For timing details and the full forecast, see NWS Portland.
Nighttime Cooling Will Be Limited
Overnight lows will generally sit in the mid 50s along the river and in the upper 50s to mid 60s inland, offering only modest relief from the hot afternoons. Limited nighttime cooling can increase heat stress for people without air conditioning and make sleep uncomfortable across the interior lowlands. Keep an eye on vulnerable neighbors, and consider shifting strenuous outdoor work or exercise to the morning or evening hours.
Marine Conditions And Small Craft Advisories
Coastal waters will see strengthening north-northwest winds during the afternoons, with gusts up to about 30 mph and a fresh northwest swell making seas steep, with waves around 6 to 7 feet in spots. Small Craft Advisories are in effect from Saturday afternoon into Sunday night for much of the central and southern coastal waters, so recreational boaters should steer clear of exposed areas during advisory periods. Check the latest marine forecast before heading out and secure loose gear at marinas.
Heat Safety And Cooling Options
Multnomah County and the City of Portland can open cooling centers when heat thresholds are met, and TriMet will allow riders to travel to cooling sites during a declared heat emergency. Local guidance and current lists of cooling locations are available at Portland.gov. Drink plenty of water, limit strenuous activity during the hottest part of the afternoon, and check on friends, family and neighbors who may lack reliable cooling.
Plan outdoor activities for the cooler morning or evening hours, stay hydrated, and keep an eye on forecasts over the next few days as the ridge of high pressure peaks. We will update if watches or advisories are issued or changed.
