We just finished a cool, dry May in Chicagoland — with a dust storm, too. What will June bring?

The calendar switched to June 1 on Sunday, officially kicking off the three-month period of meteorological summer — June, July and August.

But without the aid of a calendar, Chicagoland residents may have been confused, because it sure didn’t feel like summer was coming over the previous couple weeks.

The second part of May was unseasonably cool, and the line of demarcation was a rare dust storm in Chicagoland.

Daily highs were very warm at O’Hare International Airport from Monday, May 12, through Friday, May 16, with the mercury soaring to 94 degrees on Thursday, May 15. But after that strange dust storm kicked up on May 16 (see more below), Chicagoland plunged into an unrelenting pattern of cool temps for the rest of May.

The average high temp for late May is in the mid-70s, but there were only two readings of 70 or above at O’Hare after Saturday, May 17, and those came on two of the final three days of the month.

In fact, the high at O’Hare didn’t even reach 60 for four consecutive days from Monday, May 19, through Thursday, May 22, bottoming out with a chilly high of 52 on Wednesday, May 21.

On our scorecard of temps of 80 or warmer, we’ve racked up only a handful so far this year at O’Hare, with a few more at Midway International Airport.

We will add two more, however, on Monday and Tuesday of this week as June begins.

Dry conditions

While the end of May was unseasonably cool, it was not unseasonably wet.

May is typically our wettest month of the year, with about 4 1/2 inches of rain on average, but we were way behind on that amount — and well behind for the year.

Since Jan. 1, we’re down by more than 5 inches of precipitation.

Some of that has to do with our lack of snowfall this past winter, but we’ve also just seen a dry May, with only 1 1/3 inches of precipitation, when we usually get more than 4 inches of rain in May.

Not surprisingly, all of Chicagoland is under some form of drought at the moment. The USDA’s Drought Monitor, released every Thursday, places most of us in the area considered either “abnormally dry” or “moderate drought.”

But there are far worse drought conditions on the Great Plains as we get deeper into planting season.

Perhaps June will ease the drought conditions in Chicagoland, since it’s our third-wettest month of the year on average, with about 4.1 inches of rainfall. August is our second-wettest month on average at 4 1/4 inches of rainfall.

But May is our wettest month on average, and we just finished a very dry May, so who knows what June and beyond will bring?

Rare dust storm

The dry weather really showed up in a visual way during May that we rarely see around here.

On Friday, May 16, strong southerly winds picked up a lot of dirt from non-yet-planted fields in central Illinois and hurled it toward Chicagoland in 60-mph gusts as a dark wall of dust.

Dust storms are something we see more often downstate, or out in more arid parts of the western U.S. The last time we had a big dust storm in Chicago was more than 30 years ago, and our biggest ever was part of the “Dust Bowl” atmospheric phenomena in the 1930s, almost a century ago.

But that Friday event in May was the first Dust Storm Warning ever issued for the City of Chicago proper.

Water temps rising, but still cold

Lake Michigan water temps are on the rise as we begin June.

Over Memorial Day weekend, we had our first water temp of 60 this year along the Chicago shore. Since then, however, we’ve backed those temps off to the mid- to upper 50s.

That means the water is still dangerously cold, which is important to keep in mind as you get out and enjoy area beaches during the start of summer.

Water colder than 70 degrees can zap a swimmer’s energy very rapidly. As air temps warm up significantly Monday and Tuesday this week, make sure to wade into the water and not just jump.

And, as always, keep lifejackets on kids anywhere near water. Remember, nearly all drowning deaths are preventable ones.

Temps climb in June

While Monday and Tuesday will be much warmer than average, our extended temperature outlook into the first part of June is at or below average.

But that doesn’t necessarily mean cold, since the average high is now in the mid-70s. Average high temps later in June climb into the 80s for highs and the 60s for lows.

The cooler-than-normal temps that have endured in Chicagoland lately are all part of a really wavy jet stream pattern that seems to have a root cause, in part, in the North Pole vortex that’s being knocked again out of the Arctic Circle. This is sloshing colder temps into lower latitudes, where we all live.

Long days ahead

Get ready to enjoy long days and plenty of sunlight, because the longest days of the year are ahead in June.

We’re already getting sunsets past 8 p.m., and our longest days of the year happen in the northern hemisphere around the Summer Solstice on June 20.

As we get into June with the long days, don’t forget the sunscreen! Around lunchtime, all it takes is about 20 minutes on a sunny day to get a sunburn.