A classic springtime pattern is unfolding across New South Wales, chilly nights are mixing with hot days, something that went missing in spring 2011 and 2010. Clear skies and dry air are largely responsible, allowing any daytime warmth to escape at night. The atmosphere became noticeably drier during the last few months and it also dried out a fair bit last weekend, when a strong cold front moved through. Chilly nights set once winds eased in the wake of the front and now winds are turning north-westerly, drawing heat from central Australia. Some places this week are experiencing frost then 30-degree heat in the space of just two-or-three days. Coonabarabran in the central-west chilled to zero degrees on Monday and is likely to reach 30 degrees tomorrow or Saturday. The heat will peak today in the far south of the State, tomorrow in central parts and on Saturday in the north, reaching the low-to-mid thirties, as much as 10 degrees above average. A gradual change will then cool days and nights a few degrees below average with a chance of light frost in the south. The exception is in the north, where 30-degree days may continue into next week. We will have to wait a bit longer before we see 40-degree heat anywhere in the State but not as long as in the last two years. In 2011 it took until November 7th to reach 40 degrees. In 2010 it stayed below 40 degrees throughout spring.