MONTREAL (AFP) - A region in western Canada has notched up a record-high winter temperature, just months after the country sweltered under a historic global heat dome in the summer, causing global concern about climate change.

Penticton, a city in central British Columbia, on Wednesday (Dec 1) recorded a high temperature of 72.5 degrees Fahrenheit (22.5 deg C).

"It is a record, or it equals a record, to be very precise," Environment Canada meteorologist Armel Castellan told AFP.

Winter temperatures in Canada had previously hit 72.5 degrees Fahrenheit on Dec 3, 1982 in the south-eastern town of Hamilton, Ontario, Mr Castellan said.

Penticton is located a few hundred miles south-east of Lytton. Located 250km north-east of Vancouver, Lytton gained international attention over the summer for setting a new Canadian heat record of 49.6 deg C before being ravaged days later by a fire that killed at least two residents.

The province of British Columbia also suffered over the summer from the historic heat dome linked to climate change that saw hot air trapped by high pressure fronts over western Canada and the western United States.

The heat wave exacerbated wildfires and claimed hundreds of lives.

"Since September, we've had a lot of heat coming in from the subtropics," Mr Castellan explained.

For the past week or so, an "atmospheric river" has been raging across southwestern British Columbia, the third so far, he said.

Heavy rainfall has caused catastrophic flooding in the province since mid-November, which authorities have also linked to the effects of climate change.

The winter heat has also spread across the northwestern United States, where the states of Washington, Montana, Wyoming and North Dakota either equaled previous record-highs or hit new ones on Wednesday.

Temperatures were up to 35 deg Fahrenheit above normal.

The warm front moved towards Omaha, Nebraska on Thursday, reaching a new record temperature of 68 deg Fahrenheit.

Authorities in California are considering implementing a heat wave warning system next year that would classify each wave according to the number of potential deaths, in order to encourage preventative measures.

Recent studies show that climate change is directly responsible for some of the heat waves.

The one that hit Canada in June would have been "virtually impossible" without human-caused global warming, the World Weather Attribution science consortium said.