It was very, very hot in Perth, Western Australia, on Monday.

The temperature reached 44.4C at 1.07pm, making it the city’s sixth-hottest day on record and the hottest day in 18 years.

This won’t be news to any Perth readers, most of whom retreated inside around midday as it became clear the city was in for a rare too-hot-for-the-beach day.

The Bureau of Meteorology (Bom) duty forecaster, Callum Stuart, told Guardian Australia the uncomfortably warm weather was caused by a strong north-easterly wind, which brought heat from the state’s interior to the city. That, combined with a weak sea breeze, led to the city’s sixth hottest day on record.

Stuart said it seemed unlikely the temperature could climb to reach fifth position – 44.5C on 26 February, 1997 – but he had not expected the temperature to keep climbing once it hit 44.1C.

“The winds have turned around from the direction of the ocean now but I can’t say either way whether it could get any hotter. It’s already bloody hot,” he said.

The hottest day recorded in Perth was on 23 February, 1991, when the mercury reached 46.2C.

The Bom’s three-day forecast for Monday shows a severe heatwave in the Pilbara and Gascoyne regions and a low-intensity heatwave across the south-western third of the state, which stretches into South Australia, Victoria and Tasmania.

It will release its annual climate statement for 2014 on Tuesday.