New South Wales in December 2017: Very warm nights and wet in the south

New South Wales was warmer than average in December, and the second-warmest December on record for minimum temperature. Rainfall was around average for the State overall, although large areas of the south and west received twice their monthly average due to heavy rains at the start of the month.

A wet start in the south

  • Rainfall in December was around average overall for the State, 23% above the December mean
  • A strong cold front interacted with a mass of humid air at the start of the month bringing heavy rainfall to the south and west; large areas received more than twice their average December rainfall for the month in the first week and several stations had their wettest December on record
  • Many stations in the Riverina, South West Slopes and Lower Western districts had their wettest December day on record in the 24 hours to 9am on the 2nd
  • Below average monthly totals were recorded in the North West Slopes and Plains, Hunter and Upper Western districts

Summer begins with warm nights

  • December 2017 was the seventh-warmest December on record for New South Wales, 2.00 °C above average
  • The State's mean maximum was 1.80 °C above average, with maximum temperatures above average across most of the State away from the southwest
  • The State's mean minimum was 2.20 °C above average, the second warmest on record for December; many stations from the Hunter District down to the South Coast had their warmest December minima on record
  • Several sites around Sydney had their warmest December day on record on the 19th and 20th, and a number of stations across the State had their warmest December night (highest daily minimum temperature) on record from the 18th to the 20th during the State's first heatwave of the summer
  • Temperatures in part of the northwest stayed above 30 °C from the 18th to the 20th; the minimum temperature at Tibooburra on the 19th was a record warm 33.5 °C, the second-warmest December minimum recorded in the State, and the fourth-highest minimum temperature recorded at any time of year

A stormy Christmas in the northeast