Roebourne on the Western Australia Pilbara coast has just set a new December heat record for the state with a scorching 49 degrees, only 0.5 of a degree short of the Australian December record. Roebourne's airport reached 49.0 degrees, just beating the town's maximum of 48.9, which was also yesterday afternoon. These temperatures are 10 degrees above average for this time of year. Temperatures this high don't normally occur until January or February. Prior to yesterday, WA's previous record high December temperature was 48.8 degrees, recorded in 1986 in nearby Mardie. Birdsville still holds the national December record of 49.5 degrees, set in 1972. Yesterday's heat had been in the making for several days, with help from plenty of sunshine and unseasonably warm waters offshore. On Tuesday this week Marble Bar had reached 47.1 degrees. Yesterday the inland Pilbara town reached 48.3, which is equal to its December record. The inland was relatively cool compared to the coast, where easterly winds helped break heat records. Onslow, on the coast, set a new personal December record of 47.9 degrees yesterday, 12 degrees above average. The next few days show signs of cooling down to the low 40s near the coast, much closer to average. For inland areas, including Marble Bar the cooling will be minimal. The temperature should still reach 45 degrees until at least Christmas Day, when cloud increases. The Pilbara is unlikely to see any cooling showers or thunderstorms until then.