Alice Springs has just had its longest run of May heat in 71 years of records. The town has reached 30 degrees on every day this May except one, when it reached 29.9. This makes it the longest string of temperatures this high since records began in 1942. The current average this May is 31 degrees, eight above the norm. The very warm days have also been accompanied by warm nights. This morning it only dropped to 18.2 degrees, 10 degrees above average and the second warmest May night in the last decade. Saturday will be the last of the warm days though with a trough bringing a cool change on Sunday. This will bring more normal May temperatures with a top of 23 forecast for Mother's Day. The trough will also bring the first significant rain since March when nearly 20mm fell. Rainfall totals of 10-15mm can be expected on Sunday with up to 25mm possible. The start of the working week will be even cooler with maximums staying in the teens until at least Wednesday. Tuesday is looking to be the coolest day with the mercury set to reach just 17 degrees, six below average.