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 that 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 with wild winds blowing across the city, causing havoc and bringing cooler temperatures.

Data from the Bureau of Meteorology shows the temperature at Observatory Hill barely dipped below 20 degrees overnight, topping 22 degrees at sunrise.