Portland will get one more sunny day Wednesday with average temps in the low 80s before a more persistent heat up kicks in on the Fourth of July.

There may be a few morning clouds in the metro area Wednesday, but skies should gradually clear to mostly sunny by the afternoon. The high will be about 82 degrees.

The National Weather Service says Thursday will be the first day in a long string of hot days that will extend into the weekend and likely into early next week. Winds will be north/northeasterly and will shut off the cooler air we get when they blow northwesterly. An excessive heat warning begins Thursday afternoon and now continues through Sunday. It may be extended.

Your Fourth of July will be sunny all day and the high temp will reach about 92 degrees. Which is still plenty hot. Folks who plan outdoor activities to celebrate the holiday should use caution and plan for plenty of time in the shade or indoors in cool areas. Drink plenty of water and watch for signs of heat stroke, especially in younger children and the elderly.

Friday will be the first in a string of at least three days with triple digit heat. High temps are likely to hit 102 in the metro area. Saturday will be even hotter as temps climb to about 105. Currently probabilities of temps higher than 105 degrees on Friday are 20-50%. On Saturday those chances rise to 60-80%. The highest chances are along the Interstate 5 corridor at elevations below 300 feet, according to the weather service.

Another factor creating uncomfortable conditions and health concerns are the overnight low temperatures which will not cool enough to give residents without A/C or other cooling methods much relief. The overnight low on Friday is near 68 degrees, and on Saturday will be about 69.

Sunday was initially supposed to cool down below 100, but current models show another hot day with highs near 104. There’s a 70% chance of temps of 105 or hotter in urban areas around Salem, Hillsboro, Portland, and Vancouver.

There’s high confidence in forecast models that show a continued period of hot temperatures into the middle of next week. NOAA’s Climate Prediction Center is keeping the entire region under a moderate risk of excessive heat through July 12. The weather service warns residents that they “should be prepared to deal with the cumulative effects of long-duration heat into at least the middle of next week.”