Sydney Marathon 2025 got off to a chilly start this morning, but the rest of the day is shaping up to be a cracker for those hopefuls looking to finish the race and for the spectators cheering them on along the way. 

The race kicked off in North Sydney at 6:30 am, not far from the Weatherzone office, under perfectly clear skies, allowing the temperature to hover a tad over 8°C as the race began. But westerly winds persisting in the wake of a polar air mass, which brought snow to the Blue Mountains yesterday, meant that the temperature only felt about 3°C, urging runners to get moving just to get warm. 

Image: Observations at marathon start time of 6:30 am, Sunday, August 31, showing an actual temperature of about 8°C in westerly winds over Sydney.  

Images: The sun shines on marathon runners crossing Sydney Harbour Bridge (top) while spectators gather along Anzac Parade (bottom) under perfectly clear skies at around 7 am, Sunday, August 31. Source: Live Traffic NSW 

With only four hours left until the race cut-off time of 3:15 pm, those perfectly clear skies look set to continue for the remainder of the marathon. At the time of writing, the temperature has climbed to a little more than 17°C, although those westerly component winds are still persisting, making the temperature feel more like 14°C. As you can see from the forecast map below, temperatures are expected to climb to about 18-19°C today. An easterly sea breeze is expected to develop in the early afternoon, making the temperature feel just a tad cooler at about 17-18°C. 

Image: Forecast winds and temperature at 3 pm, Sunday, August 31, according to the high-resolution Access-C model. 

Perfect conditions to celebrate the completion of this year’s Sydney marathon! Enjoy the beautiful Sydney weather today!