This October long weekend many Australians would be forgiven for thinking Christmas had come early. From South Australia to New South Wales a long October warm spell is kicking off, with summer-like temperatures taking hold. Beginning today, Adelaide is set to exceed 30 degrees for four or five days running. If the run successfully lasts four days, then it will be the earliest such spring run on record, occurring two weeks earlier than the previous record. There is a similar story across the rest of the southeast. Melbourne will also see its warmest five-day run this early in spring on record. Parkes should have its earliest five-day spring run over 30 degrees. In Sydney, the city should have three or four days over 30 degrees. While western Sydney will reach the mid 30's each day from Saturday to Tuesday or Wednesday. This will be the hottest October run for the Sydney basin since the record setting hot spell of 1998. It will be a marvelous weekend for BBQ's, picnics and grand finals with clear skies coinciding with the hot weather across southern and eastern Australia. It may even feel like a classic Australian Christmas, with people flocking to the beaches to cool off. The reason for this exceptional spring heat is a slow-moving high pressure system. A large high is currently situated over NSW and will edge its way into the Tasman Sea, with northerly winds filtering heat from inland Australia to the coast. It is rare to see such a slow moving weather pattern at this time of year, with fast moving fronts and windy conditions much more typical spring weather.