Sydney has just endured its coldest day so far this year, as long as it doesn't warm up too much before 9am tomorrow. Cloud and rain helped keep the mercury down across the Sydney Basin cool today, with temperatures struggling to reach the mid teens in some areas. As of 5pm, the maximum temperature in the city was 14.3 degrees. This is three below average for June and the coldest day since August last year. It was also the coldest day since last winter in Penrith, where the temperature had only reached a top of 12.1 degrees as of 5pm. These statistics will stand as long as the temperature does not climb any higher by 9am tomorrow. This caveat is the result of a meteorological day being measured as the 24 hours from 9am to 9am. Thursday will be a bit warmer across Sydney as sunnier skies return, with temperatures expected to reach 17 to 18 degrees in the east and west.