Perth, Rockingham and Mandurah are sweltering through the second of a six day severe heatwave.
Mandurah hit 36C on Tuesday with the mercury tipped to reach 38C on Wednesday and 38C on Thursday.
The temperature is expected to remain over 30C until Monday prompting a heatwave warning from the Department of Health.
Bureau of Meteorology's Jessica Lingard said this type of weather is unusual for November.
"We have never had a severe heatwave warning in November," she said.
"These types of weather conditions are fairly unprecedented and it does look like we could set a fair records across the metro area this week."
The Department of Health is urging people to try and stay cool over the next few days to help prevent heat stress and heat stroke.
RSPCA WA is also reminding pet owners to keep their animals inside or at least under shelter with plenty of water.
Inspector Manager Kylie Green said just a few simple actions can keep pets safe and comfortable.
"Make sure pets have access to shade, or better yet, bring them inside in the cool," Kylie said.
"Give them access to plenty of cool water—always more than one source in case one gets knocked over—and consider setting up a clam pool or similar for them to splash around in.
"Don’t tie dogs up and leave them unsupervised – we’ve seen cases where they tangle their tether, leaving it so short they can’t get to shade or water which has led to heatstroke deaths.
"Bring smaller pets inside, including birds, and give rabbits, guinea pigs and rats cool toys like frozen water bottles to lie on.
"Don’t walk your dog in the heat of the day—remember, if you can’t leave your hand on the road, footpath or sand at the beach comfortably for five seconds, then their paws will burn."
The Public Transport Authority is also advising commuters to allow extra travel time as trains may be placed on temporary speed restrictions due to the heat.
Transperth reduces the speed of trains by about 20km/h when track-level temperatures reach 37C on the Fremantle, Midland and Armadale lines and 39C on the Mandurah, Joondalup and Thornlie lines.
Three walk trails (Stacey's Loop, Baldwins Bluff, Kittys Gorge Trail) are also closed in the Serpentine National Park.