It was another hot August night for Sydney residents with the temperature warmer at midnight than it was at midday on Tuesday.
Sydney residents awoke on Wednesday to temperatures which were up to 20 degrees above average for this time of year in some parts of the greater metropolitan region.
But the run of warm, sunny days is set to finish towards the end of the week with cooler temperatures and rain forecast.
Data from the Bureau of Meteorology shows the temperature at Observatory Hill barely dipped below 20 degrees overnight, topping 22 degrees at sunrise.
The temperature topped 24 degrees in Penrith and Richmond, with Weatherzone senior meteorologist Brett Dutschke describing the warmth as highly unusual.
"For most of Sydney it was warmer at midnight last night than it was at midday yesterday," he said.
"In some parts of Sydney, the temperature is 10-15 degrees above average for this time of year.
"It is quite extraordinary. In Richmond for example, it was 24 degrees at sunrise. Typically it's about 20 degrees colder than that."
The balmy temperatures are caused by wind stirring up residual warm air from Tuesday.
The smoky haze caused by hazard reduction burning earlier this week has largely cleared but Office of Environment data shows air quality is still poor in some parts of Sydney.
St Marys, in Sydney's west, and Oakdale, in the south-west, both recorded poor air quality but for the majority of the city, air quality was either good or very good.
The temperature is forecast to reach a top of 23 degrees on Wednesday but a cool wind will bring lower overnight temperatures followed by a warm day on Thursday with 24 degrees expected.
Data from the Bureau of Meteorology shows the temperature will struggle to rise above 20 degrees for the latter part of the week with rain forecast for the weekend.
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