The GTA, including Toronto, is under a heat warning and thunderstorm watch as sweltering temperatures hit the region on Friday.

Environment Canada said it is tracking a line of severe storms that are capable of producing very strong wind gusts, up to nickel size hail, and heavy rain in the afternoon.

Temperatures are expected to reach the low- to mid-30s with afternoon humidex values of 40 or higher.

The heat warning from Environment Canada was issued on Thursday, ahead of the extreme heat that is expected to continue into Saturday.

680 NEWS meteorologist Jill Taylor said the high on Friday will be 33 C with the humidex near 47.

Although it will be a hot one, Taylor said the GTA is not expected to break any heat records on Friday. The record high on this date was 35.6 C in 1946. The highest humidex ever recorded at Pearson airport was 50.3 on July 14, 1995.

There won’t be much relief overnight as the temperature will only be dropping to the low- to mid-20s, with humidex values remaining near 30.

Scattered showers and thunderstorms are also expected on Saturday, along with some sun. The high is expected to hit 34 C with the humidex near 47.

Cooler air is expected to move through the area on Sunday.

The weather agency is reminding people to never leave pets in parked cars.

If you are heading to the beach in Toronto, keep in mind that some locations are unsafe to swim at due to bacteria. Click here for the latest swimming conditions.