Southern Ontario is about to get its first blast of warm weather this year. Here's when

Temperatures in Toronto are about to soar, with record-setting days potentially in store. (The Canadian Press)

Temperatures in Ontario are expected skyrocket this week with the first blast of warm weather forecast for St. Patrick's Day.

According to The Weather Network, temperatures across southern Ontario could “easily” reach between 15 C and 19 C on Thursday.

"For some, this will be the warmest St. Patrick's Day in over 10 years," The Weather Network meteorologist Kelly Sonnenburg said.

The seasonal daytime high for this time of year is 4 C. These temperatures are more consistent with late April or early May for southern Ontario, The Weather Network said.

Environment Canada is forecasting temperatures in Toronto to hit 17 C on Thursday under sunny skies.

The last time it was 17 C on St. Patrick's Day was in 2010 when it was 17.7 C. It would also be Toronto's first St. Patrick’s day with double-digit temperatures since 2016.

Sonnenburg said it won't be Toronto's hottest St. Patrick's Day on record though. In 1945, Toronto hit 19.4 C on March 17.

In Barrie, Kitchener and Ottawa, the temperature is expected to hit 14 C on Thursday.

In London, temperatures will be slightly warmer at 15 C.

Northern Ontario will also experience a warmer-than-average day. Temperatures in Sudbury forecast to hit 11 C, which is the highest its been on St. Patrick's Day in a decade.

Unfortunately, the warm weather isn't expected to last. Toronto is expected to dip down to 5 degrees on Saturday and there is even a chance of flurries on Sunday.