Whoever wished for a warm Fourth of July may have put a little too much effort into it.

After a relatively temperate stretch, Portland is heating up as it heads into the Fourth of July weekend.

“Today, tomorrow and Wednesday are all normal in regards to temperature,” Tyler Kranz, a lead meteorologist at the National Weather Service in Portland, said Monday, noting the high temperatures will stay in the 70s and 80s.

On Thursday, things will start to shift.

“Thursday, July 4, is the first day of the heat wave,” Kranz said.

On the holiday, temperatures are expected to peak in the afternoon in the low 90s. It will feel hot, but that will just be a warm-up for the next few days.

“Our confidence is growing that we will be well into the 90s, if not at 100 degrees,” Kranz said.

The probability of temperatures at 100 degrees or warmer on Friday, Saturday and Sunday is currently 50 to 60%, he said.

Monday could also get that hot, he added, though the probability for triple-digit temperatures drops to 15 to 30%.

“Long story short, it’s going to be hot,” Kranz said.

While Portland probably won’t hit a record on the Fourth of July, the next three days are all up for grabs, with standing records at 95 to 98 degrees.

“It’s safe to say July 5th through the 7th, record-breaking heat is becoming increasingly likely,” Kranz said.

While the air may be hot, it’s important to remember that local waterways will still be quite cold.

“Water temperatures are in the 50s and 60s,” Kranz said. “That is definitely cold enough to get ‘cold water shock.’”

If you plan on swimming in a lake or river, wear life jackets, be aware of currents and water temperatures and stay within an arm’s reach of your children.

Read more: Thinking of escaping the heat at the river? Read this first

– Lizzy Acker covers life and culture and writes the advice column Why Tho? Reach her at 503-221-8052, lacker@oregonian.com or @lizzzyacker

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