Sydney's warm days are coming to an abrupt end, with a cool change just around the corner. It has been a hot end to the working week in Sydney, with daytime temperatures sitting above average since Wednesday, thanks to warm northerly winds ahead of an approaching low pressure trough. On Thursday Sydney maxed out at a sultry 32 degrees, ten above average, while last night it only cooled to 20 degrees in the city. This made it Sydney's warmest October night in four years. Friday morning was also toasty in the state's capital. It had already warmed to 30 degrees by 10am and it is expected to reach close to 32 degrees in the city and even hotter in the west. As the trough moves over the city early this afternoon winds will tend southerly and become gusty, bringing a noticeably sharp drop in temperature. This change has already affected parts of the South Coast this morning. Kiama cooled from 30 to 20 degrees within a period of just half an hour this morning. In the wake of this change Sydney will see cooler days and nights, with likely maximums in the low twenties over the weekend and into next week. From Saturday this trough will develop into a low pressure system over the Tasman, causing showers to develop in the morning and bringing a risk of storms from the afternoon. So the weekend's weather will come as quite a contrast to the summery days of this week.