South Australia continues to feel the heat as May temperatures soar. Parafield slept through their warmest May night in 40 years last night, dropping to just 19.8 degrees. Adelaide only dipped to 19.6 degrees, 10 above average and the warmest May night in 26 years. Ceduna followed suit with an overnight minimum of 21 degrees, a whopping 12 degrees above average the May average and its warmest May night in eight years. The warm night comes after Adelaide's hottest May day in 92 years, reaching a summer-like top of 31 degrees yesterday. The last time Adelaide saw the mercury rise this high in May was in 1921 when the record of 32.3 degrees was set. So far this autumn there has been a lack of significant cold fronts across the state, which has allowed the summer's heat to hang around for longer than usual. Over the last few days, northerly winds have filtered this inland heat through South Australia ahead of an approaching front, which looks to be one of the strongest fronts so far this season. Most of the state will remain unseasonably warm until the weekend, with Adelaide reaching the high twenties until Saturday. The front will cause showers and a cooler change to spread from the state's west on Saturday, bringing an end to the late-season heat. Showers will reach Adelaide on Saturday night with the front, before cooler southwesterly winds, cloud and showers make Sunday a noticeable contrast to the recent run of hot days. Adelaide is forecast to reach just 18 degrees, the coldest day in three weeks and the first below average for the month.