The Bureau of Meteorology has issued a heatwave warning for parts of WA this week including Perth, Rockingham and Mandurah.
Perth is forecast to hit 38C on Monday and 37C on Tuesday through to Thursday.
It will be slightly cooler in Mandurah and Rockingham which is forecast to reach 33C on Monday, 32C on Tuesday and 34C on Wednesday and Thursday.
Bureau Meteorologist Jessica Lingard said a run of hot temperatures are quite unusual for this time of year.
"It's maybe not unusual to see a day or two of these warmer temperatures but to see an entire week this late into the month is perhaps a little unusual," she said.
"For around the Perth area it has been about 40 years since we last saw a week of really hot temperatures at the end of March and there are similar statistics for around the Mandurah and Rockingham areas."
Temperatures will drop slightly from Friday into the high-20s and low 30s.
PIC: Bureau of Meteorology
Community invited to name crane towers building new Mandurah Hospital
Hundreds of volunteers remove 525kgs of rubbish from Mandurah's waterways
Port Kennedy man fined $4.2k for failing to feed horse
Rockingham General Hospital patients face the longest waits for elective surgery
Australian-first drone technology to monitor emergencies, crimes in Baldivis, Kwinana, Rockingham
Teen accused of ordering firebomb attack on Baldivis tobacco shop
City of Mandurah sees sharp rise in animal cruelty reports
Geoff Valentine returns to Peel Thunder as senior coach
Golden Bay woman charged with lacing colleague's curry lunch with snail poison