Jacqueline Sharp, (left, and her two sons, Jackson, 2, center, and Justin, 7, enjoy some shaved ice under the Walnut Street Bridge on a cool Monday afternoon.

It’s cool. And that’s weird.

Temperatures dropped to a balmy 62 degrees in the Scenic City on Monday morning, sparking a citywide water cooler debate on the cause of the unseasonable weather.

It’s an early fall, some said. All the hot air is in Washington, argued others. Hell froze over. Witchcraft. Obama’s visit today is causing the temps to drop.

But National Weather Service meteorologist Anthony Cavallucci begged to differ.

“Well, it’s probably not because of that,” he said, laughing. “We had some cool air from Canada that has filtered into the area.”

The Northern air mass is drier and cooler than the more-tropical air that typically blows through Chattanooga from the Gulf of Mexico, Cavallucci said. And that’s what’s dropping temperatures.

This month has been one of the coolest and rainiest in Chattanooga’s recent history — with rain falling on 20 of the month’s 28 days by Monday. More than 46 inches of rain has fallen on Chattanooga so far this year, which is more than 15 inches above the normal rate. Just over two inches of that rain fell on July 7 alone, breaking an 85-year-record for the most daily precipitation.

The rain is another key factor in keeping temps down, Cavallucci said.

“When the soil is wet, the temperatures are generally cooler,” he said. “Last year it was very dry for a couple of weeks, and we got really hot. If it’s really wet, it’s not going to be very warm.”

Temperatures will climb a bit as the week goes on, he added. Today’s high is expected to be 87. Wednesday will hit the mid-80s with a 30 percent chance of rain. He expects Thursday to hit 88 or 89 degrees, then a storm system will move in for the weekend, with a 50 percent chance of rain on Saturday and Sunday.

Channel 3 WRCB meteorologist Paul Barys said he expects the cool weather to last through the fall. There may be a few days that hit higher temperatures, he said, but the overall pattern will be cooler.

“My best guess on this is that we’ll have a cool August and go into a cool fall,” he said. “It’s not unexpected. This year if you look at a weather map you see a current of air coming out of the Northwest. This time of year, that brings normal to below normal temperatures.”

That’s bad news for some local businesses that thrive during soaring temps. At Reliable Heating & Air Conditioning, the cool weather has led to the slowest summer in recent memory.

“This is the mildest summer we’ve had in 40 years,” vice president David Cornell said. “This is typically our busiest time of the year. We’ve seen a noticeable drop-off in service calls because the equipment doesn’t have to work as hard. We’re still busy, but not the crazy busy we usually are.”

Up in Cleveland, Tenn., Baskin-Robbins franchise owner Brad Benton agreed that the cooler weather is having a quantifiable impact on business.

“If it’s March and it turns out to be 83 degrees, everyone wants to eat ice cream,” he said. “If it’s July and it turns out be 83 degrees, then people say, ‘Oh it’s a nice day’ and ice cream is not at the top of the list. This summer has been less than favorable, weather-condition wise.”

But over at Painter Ready, owner Ken Morris’ crew is breathing a sigh of relief.

“Between the monsoon we had and then the heat wave afterward, the cooler weather is a welcome change,” Morris said. “It’s affected us in a very positive way. It’s a better work environment.”

Contact staff writer Shelly Bradbury at sbradbury@timesfreepress.com or 423-757-6525.