Severe storms are on the way for Melbourne and parts of Victoria, as humidity in the city soars to levels more familiar to residents of Brisbane or Sydney.
While temperatures only reached 29 degrees Celsius, humidity in some parts of the city hit 90 per cent on Monday morning, and remained in the high 60s and early 70s throughout the day.
Senior meteorologist at the weather bureau Stephen King said the dew point temperature, a moisture measure which indicates what temperature air must be cooled to for dew to form, was much higher than normal.
"What we meteorologists like to look at is the dew point temperature, which is a much better indicator of how humid it is, and that's sitting around 20 degrees at the moment, which is quite high for Melbourne, that's what you see typically in Brisbane or Sydney," he said.
"In Melbourne, we're used to more dew point temperatures between 10 to 15 this time of year, or even lower, and that equates to relative humidity of 30 to 40 or even less."
It is not the first time this summer Melburnians have suffered through tropical weather - late last year the city broke records for humidity and short-term rainfall.
"We tend to get a couple of events like these each summer, but it's only for a couple of days at a time, our summers are typically quite dry," Mr King said.
The weather bureau has issued a severe storm and flash flooding warning for overnight for most parts of the state, as a low pressure system moves across from South Australia.
"Severe thunderstorms are likely to produce heavy rainfall that may lead to flash flooding in the warning area over the next several hours," the Bureau of Meteorology said.
"Locations which may be affected include Shepparton, Seymour, Melbourne, Bacchus Marsh, Wodonga and Wangaratta."
Mr King said if the rain did not bring down temperatures in the state before the end of month, March temperature averages would top those recorded in January and February.
"This year has been quite unusual, because we've just had this slow-moving blocking pattern, so it's been hot and wet over New South Wales and we've just been hot and dry, and basically nothing's really moving," he said.
"Hopefully we'll see some breaking down of that pattern ... but [there's] a lot of rain to get through in the last couple of days."ABC