It might be midway through Autumn, but the Harbour City and most of New South Wales remain bathed in sunshine, and April temperature records are continuing to tumble.
The Bureau of Meteorology (BOM) said a strong high-pressure system was behind the unseasonable heat.
In Sydney, highs of 31C are expected tomorrow and Friday, while Saturday will be 30C.
"The high-pressure systems tends to be the most stable part of the atmosphere, so those dictate what can come in and out of the area," the BOM's Craig Ryan said.
"If that's a strong system it's going to stay in the area for a while, so anything that wants to come into that area gets moved around it."
Meanwhile, temperatures in Dubbo have not dropped below 30C since the start of April.
That is a new record for the central-west city, surpassing the previous longest streak of six days.
Thursday is going to be hot in several areas around NSW, here is a breakdown of some key hot spots:
The heat has come early to Hay, in the state's central west, where temperatures are expected to peak at 39C on Wednesday.
On Monday, Sydney recorded its hottest April day since records began when the mercury hit 35.4C at Observatory Hill in the CBD.
Meanwhile, NSW Health has also issued a poor air quality warning for Sydney for today and tomorrow, due to burnoffs in the Marramarra National Park, north of the city.
People with respiratory conditions such as asthma are being told to limit their time outside.
Mr Ryan said cold fronts had not yet been strong enough to break the high-pressure system.
"The fronts that have come through are being pushed to the south, and they're not reaching NSW," he said.
"These bands are placed right over NSW. Typically they're placed a little bit further to the south."
The sunshine could end on Saturday, however.
"It's still a bit early to know exactly what's going to happen," Mr Ryan said.
"We'll likely see some rainfall, but the most noticeable thing will be the drop in temperature."
