Sydneysiders will roast through stifling temperatures on Thursday night with only a slight change on the way after a day of scorching heat.
Sydney and the surrounding areas will settle to 30C at midnight after soaring to highs of 43.7C on Thursday afternoon.
A spokeswoman from the Bureau of Meteorology told Daily Mail Australia the warm temperatures are set to remain, with little variation across Sydney overnight.
A spokeswoman from the Bureau of Meteorology told Daily Mail Australia the warm temperatures are set to remain and there will be little variation across Sydney overnight
Sydney and the surrounding areas will settle to 30C at midnight after soaring to highs of 43.7C throughout the day (stock image of women at the beach)
'We'll continue seeing really warm temperatures throughout the evening,' she said.
'There will most-likely be temperatures above 30C throughout the night - the western and northern parts of the region being the warmest.'
Holsworthy in Sydney's west was 35C at 8pm and the mercury will only fall by four degrees by midnight.
Newcastle in the north will see a similar drop and is expected to sit around 30C at 12am.
Sydney's Metropolitan, the Hunter and the Illawarra region saw the overall hottest temperatures in New South Wales on Thursday with the mercury sitting between 35C at Murrurundi Gap and 44C at Sydney airport.
The norther and eastern parts of New South Wales (pictured) saw the warmest temperatures on Thursday
Sydneysiders took to the water at Balmoral Beach (pictured) on Thursday to try and keep cool
The BoM spokeswoman said the temperatures won't drop immediately.
'Unlike the cool changes we've been seeing over the last few months, we're now in heatwave conditions and we're more likely to see a gradual shift,' she said.
Conditions are expected to ease on Friday with highs of 28C.
Temperatures will hover in the mid-to-high 20s over the weekend and throughout next week.
The heatwave comes as firefighters braced hellish fire conditions around the state as winds picked up.
The Box Hill and Nelson fire is burning just 40km from Sydney's CBD.
The Box Hill and Nelson fire is burning just 40km from Sydney's CBD, and could prove a threat to nearby homes
Residents in the Hills District have been told there is still a heightened level of threat to homes and to remain vigilant.
Firefighters have also issued an emergency warning for a fire at Big Jack Mountain Road in Rocky Hall, an area in the Bega Valley, and the Adaminably Complex, in Snowy Monaro.
'If you're in Mt Durragh, Rocky Hall or Wyndham areas, your plan is to leave or you're not prepared, leave now towards Pambula. Leave only if path clear,' NSW Rural Fire Service wrote on Twitter.
A Rural Fire Service firefighter Trevor Stewart views a flank of a fire on in Tumburumba on the South West Slopes regions at the western edge of the Snowy Mountains
AUSTRALIA'S THREE DAY WEATHER FORECAST:
Thursday: Min 23, Max 37
Friday: Min 23, Max 29
Saturday: Min 22, Max 27
Thursday: Min 25, Max 34
Friday: Min 25, Max 34
Saturday: Min 25, Max 31
Thursday: Min 15, Max 22
Friday: Min 13, Max 23
Saturday: Min 15, Max 25
Thursday: Min 15, Max 22
Friday: Min 15, Max 24
Saturday: Min 16, Max 26
Thursday: Min 16, Max 21
Friday: Min 13, Max 21
Saturday: Min 15, Max 24
Thursday: Min 15, Max 28
Friday: Min 16, Max 31
Saturday: Min 19, Max 34
Thursday: Min 25, Max 31
Friday: Min 26, Max 32
Saturday: Min 26, Max 33
Thursday: Min 19, Max 31
Friday: Min 14, Max 28
Saturday: Min 15, Max 31