It's officially the hottest Sept. 12 in Winnipeg on record.

Environment Canada reports the mercury hit 34.3 C at the airport in Winnipeg by 4 p.m., breaking the previous record for Sept. 12 of 33.3 C, set in 1952.

The record-setting heat was the result of a number of factors that converged over southern Manitoba all at once, said Natalie Hasell, a warning preparedness meteorologist with Environment Canada.

She said warming winds out of the southwest, a ridge bringing bright and sunny conditions, and a low-pressure system travelling through the north that brought warmth to the south all made for a hot and humid day in the city.

"We had all kinds of things coming together here for the conditions to be quite warm in southern Manitoba," said Hasell, who added the low-pressure system was also responsible for the hazy conditions seen across the southern part of the province Tuesday.

Red sky

Smoky skies in southern Manitoba are expected to clear overnight. (Meaghan Ketcheson/CBC)

"The flow is bringing the smoke from southern B.C.,southern Alberta, and the states of Washington, Idaho, Montana.

"While we do have fires everywhere locally in the Prairies, mainly the ones in Manitoba are not affecting air quality except in very close vicinity."

The smoke led the national weather service to issue an air quality statement for southern Manitoba Tuesday.

Hasell said the advancing low-pressure system would bring cooler temperatures starting later in the evening Tuesday, which she expected would also push the smoke outside the area.

Winnipeg wasn't the only community in Manitoba to break Sept. 12 heat records.

According to Environment Canada, the temperature hit 30.7 C in Gretna Tuesday, breaking the southern Manitoba town's previous Sept. 12 record of 28.9 C set in 1995. Further to the southwest, Pilot Mound's high of 31.3 C broke that community's previous Sept. 12 record of 31.1 C, set in 1952.

Carman, Man., was also the Canadian hot spot on Tuesday, with a high of 35.7 C.

Environment Canada is forecasting a high of 27 in Winnipeg for Wednesday, but Hasell said the above-average temperatures are expected to wane by late Thursday and into the weekend.