It has been a day of record breaking heat in Victoria, with some places having their hottest November day in over a century. A strong low pressure trough approaching the state has been sweeping heat from central Australia over the nation's southeast, leading to an extremely hot day. The Mallee was the hottest part of the state. Ouyen's rounded maximum of 46 degrees means it reached at least 45.6 degrees, which jumped past Mildura's 45.5 degrees at 3:40pm to set a new Victorian November heat record. It was the hottest day since Black Saturday for both towns. The previous state record was 45.0 degrees, set way back in 1905 at Mildura Post Office. Hopetoun Airport equalled this record at 3pm. Walpeup and Longerenong haven't had a hotter November day in at least 45 years, while Kyabram in the Northern Country had its hottest November night on record. Melbourne reached 39.1 degrees at 3:40pm, the city's sixth hottest November day in 165 years of records. Essendon and Moorabbin haven't had a hotter November day in 42 years of records, after hitting 39 degrees. The low pressure trough will reach western parts of the state this evening, arriving in Melbourne early on Friday morning. The system will bring rain, thunderstorms and a cooler day, although temperatures are likely to remain above average as the warm air mass lingers over the state. A cooler airmass will then arrive on Saturday, bringing temperatures closer to average.