Monday, 2 November 2020 - Monthly Climate Summary for New South Wales - Product code IDCKGC15R0

New South Wales in October 2020: wet and warm

There was widespread rain across the state this month, with totals generally above the monthly average. Conditions were generally warm, with daytime and night-time temperatures over 1 degree above historical averages except in the west. Storms brought heavy rain along the coast towards the end of the month.

Widespread rain, heavy along the coast

• October rainfall was above average over much of New South Wales, and very much above average in the far west, south coast and the Hunter valley.
• For the state as a whole, the monthly total of 65.0 mm was around 35% above average, and the wettest October since 2010.
• A series of troughs brought widespread rain to much of the interior over the 6th to the 8th, and again on the 24th and 25th, with a number of sites having their highest total October rainfall for at least 20 years.
• A series of low pressure systems late in the month brought bursts of very heavy rain to coastal areas south of the Mid-North Coast.
• Smiths Lake on the Mid-North Coast recorded 209.8 mm in the 24 hours to 9am on the 27th, one of a number of sites that had their highest October daily rainfall on record.
• Williamtown RAAF, with 70 years of data, and several other sites had their highest total October rainfall on record.
• After a generally dry start to winter, rainfall for the April to October (cool season) period was above average across much of the state, but remained below average in the north-east.

Generally warm conditions

• October temperatures were generally above average across New South Wales, except for the far west.
• For the state as a whole, mean daytime and night-time temperatures were 1.31 °C and 1.45 °C respectively above their historical October averages.
• There were warm days on the 4th and 17th from anti-cyclonic conditions directing north-westerly winds over the state ahead of cold fronts.
• Overnight temperatures were generally above average throughout the month.
• Some sites had their highest October mean daily minimum temperature on record or for at least 20 years.

Heavy rain and severe storms

• A succession of troughs and low pressure systems along the coast brought heavy rain and severe storms late in the month.
• Severe storms were reported in a wide area of eastern New South Wales on the 23rd and 24th, with a number of sites reporting 2-day totals of 60 to 70 mm.
• The most intense rainfall was from a transient low off Newcastle and the Mid-North Coast on the 26th.
• Smiths Lake on the Mid-North Coast recorded 209.8 mm in the 24 hours to 9am on the 27th, more than double its previous October daily record.
• Williamtown RAAF recorded 186.0 mm in the 12 hours from 4am to 4pm on the 26th, contributing to a record 2-day October rainfall of 205.0 mm.
• There were reports of large hail in the north-east of the state on the 29th, including hailstones of up to 10 cm in diameter north of Grafton.
• Heavy falls were recorded on the 31st in the Illawarra and along the south coast; falls after 9am on the 31st are counted in the November monthly rainfall totals.

Extremes Maps Records Summaries Important notes the top

Extremes Maps Records Summaries Important notes the top

Maps
	Observed	Anomaly	Decile rank
Total rainfall
Mean daily maximum temperatures
Mean daily minimum temperatures

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* note: there are gaps in the historical record at this site, so it is possible a higher value has gone unreported

* note: there are gaps in the historical record at this site, so it is possible a higher value has gone unreported

Extremes Maps Records Summaries Important notes the top

Extremes Maps Records Summaries Important notes the top