No need to check your calendar Thursday: It isn’t yet summer, even though it will definitely feel like it.

Cliff Mass, Atmospheric Science professor at the University of Washington, says temperatures in Seattle will flirt with between 75 and 80 degrees on Thursday before dipping back down to the lower 70s Friday and drop back down to the still-above-average 60s over the weekend.

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Mass says the warm days are coming from developing areas of high pressure and an off-shore flow. He says this is not completely unexpected for an El Nino year.

“Chances are this spring will be warmer than normal,” he said. “Probably not crazy warm like last year was, but it will be on the hot side and so the temperatures are going to relax back into the 60s, which is, by the way, above normal.”

There are only two days on record of Seattle hitting 80 degrees days before April 15. Mass says mid-70-degree temperatures are more typically the average maximum temperature for late July or mid-August.

“This is like mid-summer temperatures when you get to the upper-70s, so it’s summer heat, basically,” he said. “But we’re not going to stay there for that long. We’re going to go back into the 60s.”

The heat, mixed with the start of allergy season, might cause some confusion as to what season Seattle is actually going through.

Dr. Mark LaShell, allergist and immunologist at Group Health in Seattle, says seasonal allergy symptoms typically start around this time, meaning itchy eyes, runny nose, and worsening asthma.

“We’ve started,” he said. “The trees are pollinating and it’s just going to pick up from here. While the trees will stop pollinating in April, usually, the grass will begin to pollinate after that. So it’s nothing but up from here for the next couple months in terms of pollen counts.”

LaShell says tree pollen in Washington creates a “priming effect,” which can create a “double hit” for those also allergic to grass pollen.

“That kind of combination is somewhat unique up here,” he said.

To help cope with allergy season, LaShell recommends nasal sprays, non-sedating antihistamines, night time showers to remove pollen during sleep, keeping windows closed (if you can manage the heat) and air purifiers.