07/10/2012 09:28 EDT | Updated 09/09/2012 05:12 EDT

Alberta heat wave prompts warnings

Another hot day on tap today for Alberta, where high temperatures have strained the electrical grid and resulted in some rolling blackouts, is prompting warnings to stay in cool settings and limit outdoor activity.

In Edmonton, temperatures are expected to soar to 32 C. With the humidity, it is expected to feel closer to 35 C.

Calgary is expected to reach a high of 31 C.

Saskatoon and Regina are both expected to reach a high of 34 C.

Humidex advisories have been issued for east-central Alberta and southern Saskatchewan, where elevated humidity will give humidex values of 40 degrees or more.

"It is advised to stay in an air-conditioned place or seek shade when possible, drink plenty of water and limit physical outdoor activity," Environment Canada said in a special weather statement.

On Wednesday, there will be slightly less humidity in the air but it will still feel like the mid-30s, according to CBC meteorologist Johanna Wagstaffe.

Heavy power demand

On Monday, Edmonton, Calgary, Red Deer and Lethbridge were hit by rolling blackouts because of heavy load on the power grid caused by the first heat wave of the summer.

The Alberta Electric System Operator (AESO) said demand on the province's electrical system was pushed to record highs.

The province experienced 30-minute rolling outages after six power generating plants went down — four coal and two gas burning.

Three of the four coal-burning plants were back online by Tuesday morning.

AESO president Doug Simpson said there’s no reason to conclude there are problems with the system.

“We're planning, we're forecasting, we're keeping an eye on things. We're fully maximizing our inter-ties with our neighbours so we can import power. So hopefully we're prepared so we can avoid this again,” he said.

The unprecedented demand prompted utility operators to ask Albertans to:

- Shut off lights and electrical appliances that aren't needed.

- Minimize air conditioner use

- Not run dishwashers, washers and dryers.

The last time Alberta experienced rolling blackouts was 2006.

Dozens of daily temperature records fell Monday across British Columbia, Alberta, Saskatchewan and the Northwest Territories. Even Vancouver was at its hottest this year at 25 C, Wagstaffe said.