Perth has sweltered through hot and humid temperatures overnight.
The temperature only dropped to 27.3 degrees, close to the 1989 record of 27.8 degrees.
Adam Conroy from the Bureau of Meteorology says Perth can expect some relief from tomorrow.
"The highest minimum temperature we've had in Perth in January was 27.8 that was back in 1989," he said.
"We got very close to that overnight, dropping to 27.3.
"It was very close to the January record, but not quite an all time record that stands at 29.3, which we had in February of a couple of years ago."
He says while some relief is in sight, the warm weather is likely to return.
"The hot nights will leave us after this morning for a while thankfully we'll have a bit of cool weather develop after this afternoon," he said.
"Temperatures will be dropping down to a much more comfortable record but summer is still long, so it's probably not the last of the hot weather.
He said Perth had some cloud cover overnight and a lot of moisture in the air.
When that was coupled with easterly winds, that kept the temperature very high, resulting in temperatures at around 30 degrees.
"This is unusual for Perth to be this warm, it's the sort of night we only get once or twice every summer and it's been a very uncomfortable one."
© ABC 2013
06:40 EST The families of two snowboarders missing on Victoria's highest peak, Mount Bogong, say they are devastated by their disappearance.