A wild night of thunderstorms has delivered the heaviest rain in decades to parts of western NSW.

Tropical moisture feeding into a low pressure trough produced widespread showers and thunderstorms in NSW yesterday and last night.

The storms ramped up during Thursday afternoon and persisted well after dark as the stream of tropical moisture continued to stream across NSW.

Image: Thick clouds and lightning strikes over NSW on Thursday night.

By Friday morning, some areas had seen close to 100mm of rain and doubled their entire monthly averages in a single day.

A rain gauge at Condobolin (Retirement Village) received 127mm of rain during the 24 hours to 9am on Friday. This is on par with the highest daily rainfall ever recorded at the site, which was 127.2mm in January 1976. It's also well above the site's January monthly average of 46mm.

Cootamundra's 52mm during the 24 hours to 9am Friday was its highest January daily total in at least 26 years and its highest for any month since 2012.

Image: Storm clouds over Orange on Thursday. Credit: Megan Duckworth - @coffeewithmegsy / Instagram 

Other notable totals during the same period were 87mm at Murrumburrah and 56mm at Temora. For the latter this was the highest daily rainfall in a decade.

Rain and thunderstorms will continue to affect the western and southern inland of NSW on Friday, with more heavy falls likely and severe storms possible. Showers will also persist on and east of the range in NSW on Friday.

The focus of showers and storms will shift further east on the weekend and with tropical moisture continuing to feed across the state, heavy rain remains the main threat.