High humidity will hit Victoria this Australia Day long weekend

THE forecast for Saturday has been downgraded significantly, but that doesn’t mean it will feel much cooler. Here’s why.

MELBURNIANS will be spared from scorching temperatures but not the humidity this long weekend.

The city will reach a top of 27C today with a thundery shower expected to fall.

Northern and eastern suburbs — from Eltham to Ferntree Gully — are in the firing line for the thundery showers too.

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Bureau of Meteorology senior forecaster Chris Godfred said the humidity would ramp up over the long weekend with the dew point, an absolute measure of the moisture in the air, above average.

“On a typical day in Melbourne the dew point is around 10 which means we have to cool the air to about 10C to get condensation,” Mr Godfred said.

“Today the dew point will be about 15-16 and very humid.”

This man cools off to beat the heat. Photo: Quinn Rooney/Getty Images

Australia Day will be a hot and humid top of 29C with the dew point sitting at 18-19, while the relative humidity will reach 50 per cent.

He said it would be a good day for the beach with a cooling sea breeze to reach the city by the afternoon.

Mr Godfred said Melbourne’s outer suburbs would reach the low-30s.

For those hosting parties, brace for thunderstorms in the afternoon.

Swan Hill and Mildura will hit 40C, and Bendigo will reach 37C tomorrow.

A humid few days ahead for #Victoria. Dew point temperatures reaching 15-20 degrees for most central and eastern areas - that's high for Victorians! Eg: #Melbourne on Sunday - Max Temp 39C and Dew point mid-high teens. https://t.co/PTfXHEzYtN pic.twitter.com/gDynHsQw3L

— Bureau of Meteorology, Victoria (@BOM_Vic) January 24, 2018

Saturday will hit 33C — six degrees lower than previously forecast — but will still be very humid.

The relative humidity will sit at 40-50 per cent making it quite sticky.

There’s a chance of lightning and flash flooding due to the hot and humid conditions.

The Chief Health Officer has issued a health alert for Central, Mallee, North Central, Northern Country, South West and the Wimmera on January 26 and 27.

The entire state has been issued with a health alert for Sunday.

The average temperature for January is 25.4C.

Mr Godfred said Sunday will start off quite humid, with a dew point of 19, before northerly winds bring the dew point down to about 15.

But that won’t spare us from the scorching 39C expected.

“Conditions will feel similar to coastal NSW, very sticky,” Mr Godfred said.

Up to 8mm of rain is expected to fall on Monday for a top of 25C before 21C on Tuesday.

Wednesday will hit 23C with showers.