What started off to be a beautiful sunny day in Sydney has had clouds building over Sydney with help from onshore winds. This will lead to a warmer than usual night, with temperatures hovering around 24 degrees in the city. Tomorrow in Sydney, winds will turn northwesterly, allowing it to heat up to the mid 30s, at least in western suburbs. These northwesterlies may be strong enough to keep out a sea breeze and allow the city to reach the mid 30s also. The winds should strengthen ahead of a low pressure trough, which will bring a cooler change in the middle of the day and possibly a shower or thunderstorm. The change will be fresh and gusty southerly, bringing much needed relief from the heat. The temperature should drop by 10-to-15 degrees during the afternoon. Temperatures will return to normal by Friday, with mid 20's expected in the city. It will warm up by the by the weekend, creeping back up into the high 20's by Sunday.