A cold front brought welcome rain and highland snow to parts of central and southern NSW earlier this week.

Many areas on and west of the central and southern ranges in NSW received 5-15mm of rain during the 24 hours to 9am on Wednesday. Further east, some parts of the Illawarra coast collected more than 30mm in 24 hours.

Cold air behind the front even brought some fresh snow to the alpine region from Tuesday night and a dusting for higher areas of the Central Tablelands on Wednesday morning.

This week's rain comes after a prolonged period of dry weather in central NSW. Dubbo's 10mm during the 24 hours to 9am on Wednesday was its heaviest rain so far this year and equal to the amount of rain that fell during the last nine weeks combined.

Trangie (8mm) and Condobolin (9mm) also received their heaviest daily rainfall in four months from this system.

While it was good to see rain falling on dry soils during the last couple of days, this brief burst of wet weather wasn't enough to make up for the rainfall deficit from the last few months.

Prior to this rain-bearing system, most areas of western NSW had received less than 20 per cent of their total annual rainfall so far during 2018. This dry start to 2018 has seen the state's water storages reach their lowest level in nearly two years.

The total amount of accessible water across NSW was 8,481 gigalitres on Tuesday 29th May. This is just under 40 per cent of its capacity and is the lowest level since early June 2016. At this time last year, storages were just over 62.5 per cent full.

Drier weather will return to inland districts of NSW during the second half of this week as a high pressure system moves over southeastern Australia. This high will also bring a run of cold and frosty morning to kick off winter.