Severe thunderstorms bring a close to Sydney's equal hottest day so far this year. Blue skies and warm northwesterly winds allowed the temperature in the CBD to climb up to 36.5 degrees yesterday, making it the equal hottest day so far this year. Due to the prevailing wind direction, eastern parts of the Sydney Basin felt the warmest temperatures with the airport climbing to 37 degrees. A low pressure trough is held responsible for the gusty warm winds which elevated fire risk and severe thunderstorms which eventually brought relief for much of the Sydney Basin. It wasn't until just after lunch the winds swung westerly triggering showers and thunderstorms over Lithgow. As the main trough line continued to travel east over the ranges, the area and severity of thunderstorms dramatically increased. The first wave of thunderstorms brought a great light show to most suburbs however a second wave of storms brought the most dramatic impacts. Sydney Harbour (Wedding Cake West) recorded maximum wind gusts of 106 km/h, the strongest gusts felt in almost two years while Penrith clocked gusts up to 93 km/h. While winds were stronger about eastern parts, the rain bucketed down about the west. Seven Hills collecting 14mm as thunderstorms passed overhead. Nearby, Blacktown received 8.5mm with Greystanes picking up 8mm. Olympic Park cooled rapidly from 31.2 degrees at 3:40pm to just 19.7 degrees ten minutes later. Despite warming up once again after the showers and thunderstorms passed, a cooler airmass is now residing over the state bringing a very mild day. As of 11am today, it has only reached 20 degrees so far, a huge contrast to yesterday which had already warmed to 33 degrees by this time. The next few days about the harbour city will continue to be mild and mostly stable. A few very light showers are a possibility tomorrow morning, however the next best chance of heat and thunderstorms come on Wednesday with a low pressure trough.