Brace yourself: Summer isn’t over just yet in the Illinois Valley

Did you think you were going to get away with not having to use your window air-conditioning unit the rest of the summer? Dust it off and plug it in. You’re going to need it most of next week.

After a run of cool mid-August temperatures, Mother Nature is issuing a reminder that summer doesn’t end until late September. Starting this weekend, temperatures are forecast to climb steadily and peak in the mid-90s on Monday and Tuesday.

The humidity also is going to climb and push the feels-like temperature past 100 degrees. The National Weather Service isn’t yet sure that the outlook will require a heat advisory, which is issued when the heat index hits 105, but it could be close.

It may seem hotter than that, actually, insofar as we’ve all enjoyed mild temperatures recently. Todd Kluber, a meteorologist with the National Weather Service in Romeoville, said the middle of August had been “relatively comfortable,” and the outlook shows “a pretty substantial change in just a few days.”

“We’ve been running 5 to 10 degrees below average,” Kluber said, “and now we’ll swing 10 to 15 degrees above normal.”

If that weren’t enough, many municipal pools closed, although at least the pool is open at the Illinois Valley YMCA in Peru, right?

“It’s tough timing,” lamented Chris Weittenhiller, CEO at the Y. “Our pool is currently shut down for annual maintenance, reopening on Tuesday, Sept. 3.”

Many of the area’s splash pads remain open, including Washington Park in Peru. Hours are from 4 to 7 p.m. weekdays and from 10 a.m. to 7 p.m. weekends until Sunday, Sept. 1.

Riordan Pool in Ottawa is open from noon to 5 p.m. Saturday and Sunday, Aug. 24 and 25, as well as from noon to 5 p.m. Saturday, Aug. 31, and Sunday, Sept. 1.

Local residents are advised to check on their elder neighbors and pets (providing lots of fresh water and shade) and to watch for the opening of cooling centers if a revised forecast results in a heat advisory.

The one consolation is that this summer remains a mild one, even with the upcoming blast of heat.

Illinois state climatologist Trent Ford reported that July finished as the state’s 29th warmest on record with an average daily temperature 73.8 degrees. Nevertheless, there were offsetting factors, including just-when-needed rain.

“July gave us a mixed bag of temperatures, but more days last month were cooler than normal,” Ford said on his blog. “While last month also brought some intense heat, it was fleeting.”

That was especially true in the Illinois Valley, where periodic showers kept us from plunging into drought and took the edge off the heat.

The Weather Channel website reported a relatively limited number of 90-degree-or-higher days in La Salle-Peru: nine in June, three in July and, if the 10-day forecast bears out, five in August.

A more pressing concern is the lack of rain. The U.S. Drought Monitor, in an Aug. 22 update, showed an “abnormally dry” area stretching across northeast Illinois now encroaching on La Salle County’s panhandle and in Streator.

There isn’t much rain in the forecast through Labor Day weekend, which is shaping up to be pleasant. Daytime highs will slip below 90 degrees by Thursday, Aug. 29, and then below 80 by Saturday, Aug. 31.