Surprisingly low temperatures, showers, thunderstorms and moderate winds are expected to stick around for much of the NSW coast through to Saturday.
Bureau of Meteorology meteorologist Helen Reid said the gloomy conditions will linger with thunderstorms to push further to the northeast later in the week, but wind and rains to stick around across the coast.
"There is a southerly change coming through, so thunderstorm activity will be more focused in the northeast and that area of thunderstorm activity won't be as broad, but still significant," Dr Reid said.
"We don't have indications of heavy rainfall except in thunderstorms, but could be consistent rainfall with 10-15mm across widespread eastern NSW in the next few days."
Temperatures are also dipping with lows from Eden to Nowra dropping to a chilly 13 overnight on Monday.
Daily highs are also modest with Eden forecast to peak at 23 degrees on Wednesday and Thursday.
Ulladulla will be warmer through the night with forecasts of 18-19 with a forecast high of 24 degrees on Thursday.
Meanwhile with overnight lows in the mid-teens, both Bega and Nowra share the most optimistic outlook for daytime temps with forecast tops of 25 for Tuesday and Wednesday.
Likely showers heading into the weekend will see both regions drop back to 23 degrees, while light to moderate winds are likely to add a chill across the coast.
Dr Reid said the persistent overcast and stormy conditions owed to a trough over NSW fuelled by tropical moisture out of the north.
"A lot of moisture is feeding in from the tropics, the tropical convergence zone has moved into the southern hemisphere," Dr Reid said.
"And with an inland trough over NSW [expectations are for] thunderstorms through eastern NSW for the rest of the week."
Windy conditions are also expected to keep up with Saturday shaping up for rain and gusty winds.
The chance of rain starts around 70 per cent in Eden, Merimbula and Bega heading into the weekend and increasing up the coast with rain 75 per cent and 80 per cent likely through Ulladulla and Nowra respectively.
Bega will escape the worst of the wind, while Nowra is expected to see gusts reaching over 20kmh each day this week, with the coastline to bear more of the brunt.
Batemans Bay will see between 15-30km/h winds each day with Saturday afternoon the peak, while winds are forecast to reach almost 40km/h in Merimbula on Saturday.