Summer in the city carries on into autumn in once-in-a-decade event Early to rise: Swimmers watch the sun rise over the south Curl Curl rock pool. Sydney is set for another hot week, with temperatures between 27 and 30 degrees. Sydney is on target for its hottest week since January and hottest March week in a decade, with an average maximum temperature of about 29 degrees. The city has already begun its unusually warm week. On Friday, the mercury rose to 31.8, 6 degrees above the long-term monthly average and the first 30-degree day since January. Between now and Thursday, maximum temperatures will range from about 27 degrees to about 30, helped along by plenty of sunshine and northerly winds almost every day. For March to have this much warmth for this long is about a once-in-a-decade event. If the forecasts are correct, it will be the hottest March week since 2002, when the average maximum was 29.6. It will come as no surprise that March overall is almost certain to end up being hotter than February, something that has happened only 17 times in the past 100 years. Quieter-than-normal monsoonal activity in the tropics has allowed the interior to be sunnier than normal and for heat to build. This heat has combined with a slow-moving weather pattern where a blocking high near New Zealand has been deflecting strong fronts south of NSW, keeping Sydney in warm northerly winds on most days. For those who prefer more typical autumn weather, a fairly strong front will arrive late on Thursday, bringing a cooler southerly change and some rain. That should move north on Good Friday.