Hottest day of the year: What to know about Puget Sound's worst heat wave of 2016

Temperatures will rise into the 90s in many places across Western Washington in the worst heat wave of 2016.

High pressure will be building across northeast Washington and that will turn our prevailing wind flow northeasterly Thursday through Saturday. This will prevent cooler air from over the Pacific from making its way into Puget Sound until Sunday.

At 3 p.m. on Friday, it officially hit 94 degrees.

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The National Weather Service has issued heat advisories and warnings. Meteorologist Morgan Palmer explains which areas will get heat warnings versus advisories.

Excessive Heat Warning

An excessive heat warning goes into effect on Thursday, meaning temperatures could reach the 90s from the North Sound to the South Sound.

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High temperatures each day through Saturday from Seattle south will be in the upper 80s to lower 90s with some spots well away from the water in Pierce, Thurston, Lewis and Mason counties reaching the mid 90s.

At night, temperatures will fall in to the 50s except in urban locations where buildings and concrete will retain heat from the previous day.

These spots, including Seattle will only fall into the mid 60s at night. This will make it more difficult to effectively cool non-air conditioned buildings at night, adding to the misery.

Heat Advisory

Even the coast will be baking Thursday and Friday before some relief there a bit earlier on Saturday.

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Farther north, including Everett and Bellingham, it'll be a little cooler during the day, but not much. Fortunately, low temperatures will fall into the 50s for those folks at night.

Red Flag Warning

Fire danger will also be high to extreme Thursday through Saturday as the wind blowing out of the Cascades into the Western Washington lowlands will be very dry. Same goes for the coast.

Fires that occur could spread rapidly. In the mountains, the fire danger will also be high, though there will not be any lightning to spark fires there.

By Sunday, onshore flow will resume and humidity levels will come up a bit. It will still be warm Sunday, but low 80s for highs around Seattle will be a relief.

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We'll have temperatures back to normal -- in the 70s for daytime highs -- as early as Monday.

Cox Media Group