Sydney could be warmer tonight than Melbourne was today. The rivalry between Australia's two most populated cities often results in gibes about the weather - and tonight will certainly give Sydneysiders something to gloat about. Today was one of the warmest days so far this winter in Melbourne. The city had climbed two degrees above average to a top of 17.4 degrees by 5:00pm. Not to be outdone by the Victorian capital, Sydney will attempt to outdo Melbourne's daytime maximum temperature tonight. Strong winds and a warm air mass will help prevent the mercury from dropping much in Sydney this evening. The city's forecast overnight minimum of 18 degrees is nine degrees warmer than usual for August and equals the city's average maximum temperature at this time of year. While Melbourne's forecast low of 12 degrees tonight is notably cooler than Sydney's, it's still five degrees above average for an August night in the Victorian capital. Sydney's warmest August night on record was 19.7 degrees in 1885, although this won't be challenged tonight. Official minimum temperatures in Australia are recorded between 9am and 9am, so this morning's 13 degrees at 9:10am will be recorded as the official minimum tomorrow.