Warm air from the south is turning parts of Canada into temporary deserts and jungles in what experts are calling a “dress rehearsal” for a hot summer.

“What you see is what you’re going to get,” said Dave Phillips, senior climatologist with Environment Canada. “It’s going to be much warmer. Get to know how to make those mojitos. Get the linen out.”

The heat is draping many parts of the country. In Western Canada, “desert kind of air” could have residents concerned about drought, what Phillips calls “the D word.” Parts of British Columbia and Alberta, including Fort McMurray, have been issued heat warnings. Even areas not known for warm weather such as the Northwest Territories and Saskatchewan are feeling the burn.

For B.C. residents, who endured temperatures in the mid-30s with humidity on Sunday, relief may not come until mid-week when temperatures drop, said Phillips.

In Ontario, the heat is of a different kind, with tropical air coming from the Gulf of Mexico. In Windsor, temperatures smashed a more than two-decade long record hitting nearly 35 degrees Sunday.

In Toronto Sunday night, temperatures stayed above 23 or 24 degrees. “That’s almost jungle kind of humidity at night,” said Phillips, noting temperatures are climbing to possibly 31 or 32 degrees in the city Monday, about 6 to 8 degrees warmer than normal for mid-June. There have already been six days above 30 degrees in Toronto—three in May, three in June—while there were only nine by Labour Day last year.

While the temperatures are expected to break in Ontario today, Phillips said residents should watch for storms. “It’s going to break with a bit of a bang. The heat, humidity is the fuel for storms,” he said.

But not every part of Canada is seeing the mercury rise. The Maritime provinces, which have experienced cold temperatures and crop-damaging frost in recent weeks, wouldn’t mind some of the heat, said Phillips. “They say ‘bring it on.’”