SUDBURY -- Extreme heat is expected through Wednesday in these northeastern Ontario communities as daytime high temperatures mixed with humidity soar.

Environment Canada has issued its first heat warnings of the year for:

  • Chapleau – Missinaibi Lake
  • Elliot Lake – Ranger Lake
  • Gogama – Foleyet
  • Greater Sudbury and vicinity
  • Kirkland Lake – Englehart
  • North Bay – Powassan - Mattawa
  • Temiskaming Shores – Temagami
  • West Nipissing – French River

Temperatures near 30 C are expected Tuesday and humidex values will be in the mid to upper 30s.

A slow-moving cold front coming from the northwest is expected to bring cooler air and showers on Thursday providing some relief from the heat.

Heat warnings are issued when very high temperature or humidity conditions are expected to pose an elevated risk of heat illnesses, such as heat stroke or heat exhaustion.

With heat warnings, the risks are greater for young children, pregnant women, older adults, people with chronic illnesses and people working or exercising outdoors.

"Drink plenty of water even before you feel thirsty and stay in a cool place," the statement said. "Never leave people or pets inside a parked vehicle."

To report severe weather, send an email to or tweet reports using #ONStorm.