Perth is set to endure a prolonged spell of abnormally hot March weather next week, with the city on track to register its hottest five-day spell in 40 years this late in the season.

While Perth is no stranger to intense bouts of heat during summer, March is typically a time of year when temperatures start to moderate in southwestern Australia.

This March, however, is showing no signs of leaving summer behind, with maximum temperatures in Perth predicted to reach 31 to 38°C for at least the next 10 days, which is about 1 to 8°C above average for this time of year.

Next week could feature a five-day stretch with daytime maximum temperatures reaching 36 to 38°C. If this happens, it would be the first time since 1985 that Perth has had five days over 36°C this late in March.

Image: 10-day forecast for Perth, WA on the Weatherzone website.

Minimum temperatures will also be abnormally warm next week, currently forecast to hover around 23 to 26°C between Tuesday and Friday mornings. This is 6 to 9°C warmer than average for a March morning in Perth.

The impending and prolonged heatwave will be caused by the combined influence of a near-stationary blocking high pressure system over southern Australia and a potential tropical cyclone to the north of WA. These two features will interact to produce a hot air mass and direct a persistent stream of easterly winds towards Australia's west coast over the next 7 to 10 days.

Image: Daily Forecast on the Weatherzone app for Perth, WA.

While it may seem odd to have a tropical cyclone and a prolonged heatwave occurring around WA at the same time, tropical cyclones off Australia’s northwest shelf are known to promote the weather patterns that cause heatwaves in Australia.