To say Utah’s summer is over is a matter of definition. Friday did mark the beginning of “meteorological fall,” but the oblivious sun will still bake the state through this weekend.

Along the Wasatch Front high temperatures will soar into the mid- to upper-90s this weekend, up from Friday’s upper-80s. Meanwhile, the redrocks and high deserts of southwestern Utah will sizzle with triple-digit heat.

So, here is the weathery conundrum in a nutshell: Meteorological fall is a classification that seeks to more closely align the season’s beginning with temperature ranges, rather than where the stars happen to be (i.e., “astronomical fall,” in this case, tied to the autumn equinox listed on calendars as occurring Sept. 22).

Indeed, the National Weather Service on Friday declared that Utah’s “meteorological summer” (June 1-Aug. 31) set a record for being the warmest ever with an 80.9-degree average.

Scientists favor the meteorological approach, sniffing with perhaps thinly disguised disdain at the idea of the celestial cycles that so awed our ancient ancestors — along with the fear of sailing off the edge of a flat Earth or into the maws of island-sized sea monsters — should still hold sway on such matters of the seasons down here on terra firma.

With Utah due such hot daytime temperatures, it might seem the old calendar method has much to recommend it. Still, there is some evidence for the meteorological persuasion: overnight lows in Utah are becoming notably cooler.

Friday’s lows in the Salt Lake Tooele valleys were in the mid- to upper-60s, a good 10-15 degrees lower than just a couple weeks ago. And if you camped in the mountain valleys of the Wasatch Front, the mercury slid into the low- to mid-50s.

So, your choice, late summer or early fall. (But keep sunblock lotion handy during the clear, hot days, and a light jacket nearby for those starry evenings this Labor Day weekend).

The Utah Division of Air Quality does not have good news for out in the atmosphere, out where air is (not) clear: Salt Lake, Davis, Weber, Box Elder, Tooele, Utah and Carbon counties all are forecast to have “yellow,” or moderate particulate and ozone pollution levels this weekend.

Furthermore, if you suffer from grass, ragweed or mold allergies, it will be a miserable weekend. The Intermountain Allergy & Asthma website on Friday reported grass pollen at “very high” levels, while ragweed and mold were “high.”