Mr Jackson owns a sheep and cattle property in the northern town of Guyra, in the New England region of the state.
He said that since the start of the year his property has seen 200 mm of rain, a welcome relief for cattle and sheep that have lacked green grass to eat.
"My stock are now eating grass, which is certainly something unique for a number of them. They have got to reacquaint themselves with the colour green.
"There are two-year-old sheep and they have hardly seen any green grass. It has been quite a serious rainfall deficit for some time."
An east coast low over the weekend brought torrential rain and strong winds to the Sydney basin, which had its heaviest rainfall in up to two decades, according to the Bureau of Meteorology.
Sydney, the Central Coast and the Blue Mountains received between 200mm and 400mm of rain from 9am Friday to 5pm Sunday, with additional rain expected throughout the week.
The Insurance Council of Australia said it registered at least 10,000 claims, estimated to be worth $45 million as of 7am Monday.
'Out of my experience'
Mr Jackson said the "triple whammy" of fire, drought and now rain this season has been unprecedented in his living memory.
Source: SBS News/Lucy Murray
"It's out of my experience range. I have been managing the family farm since the mid-1980s and certainly it is out of my lived experience," he said.
"We've learnt something about our business, which we didn't know. And yes, we've been caught short. There has been some issues if I had my time again, I would have dealt with in response to this drought."
Sydney experienced the heaviest torrential rainfalls since February 1990 when ex-tropical cyclone Nancy struck.
The Bureau of Meteorology said some locations along the NSW coast saw record rainfalls of between 600 and 700 mm of rain.
NSW residents posted videos on social media, noting that dry creek beds were now flowing with water after the weekend's deluge.
"Preliminary figures suggest that Robertson in the Illawarra has received 698 mm since Wednesday; and over 500 mm of that fell over the weekend," the bureau's acting NSW manager, Jane Golding, said.
She said the heavy rain could hang around for the next week.
"The widespread rain looks like it is more than likely finished from this coastal trough. But that tropical moisture that has been really feeding those high rainfalls is still circulating over NSW and is not really expected to go away for the next week.
"So we are expecting thunderstorms to pop out every day over eastern NSW this week."
Source: Bureau of Meteorology
More rain events needed
That is welcome news for farmers who happen to have been in the areas where the rain fell the heaviest in the state's north and along the coastline.
Mr Jackson said his farm did receive rain, but that was not the case for other farmers.
"This rain event has seen the rain spread further west, but it has been patchy. Some people have missed out."
He says the drought has financially devastated many rural and regional economies.
"The drought has gone well beyond the farm gate and is essentially hollowing out the economies of rural and regional NSW."
He believes many farmers are hoping the rain will help them farm a winter serial crop that will see the money flow into drought-affected communities from December.
"This rain is starting to build a moisture profile in some areas. We need a couple more of these events and we need a planting rain in May or June.
"So this is the start of putting the jigsaw puzzle together. It is certainly not the end.
"Let's hope we get to use this moisture and get some of these bank balances [of farms] into the black."
The New South Wales Department of Primary Industry has previously declared the entire state as drought-affected.
The dry conditions have lasted for two years, with the December rainfall only 20 per cent of the average.
But Mr Jackson said farmers in the northern town of Walgett, further inland, have been experiencing drought conditions for longer than two years.
"Certainly in New England [where my farm is located], we haven't seen the worst of it. The guys in Walgett you know they are in the seventh year of drought."
NSW DPI spokesman Cameron Lay said the weekend's rain would rejuvenate the aquatic eco-system but would also present hazards with the ash and debris run-off from the bushfires.
"The resumption of flow and subsequent replenishment of refuge holes and connectivity along waterways will provide long-term benefits to native fish populations during the current drought period," he said on Friday.
"Unfortunately in the short term, heavy rain following drought can wash organic matter and sediment which has built up during the dry period into the rivers."
Kangaroo spotted swimming in NSW floodwaters
Sydney dam levels at record high
Dam levels across greater Sydney have spiked more than 20 per cent amid heavy weekend rainfall, with enough water for as much as 150,000 Olympic size swimming pools flowing into Warragamba Dam.
Water NSW data on Monday morning showed that greater Sydney dam levels were at 64.2 per cent, up 22.3 per cent in seven days.
Last month, the Bureau of Meteorology released the 2019 Annual Climate Statement, indicating that the last year was the warmest and driest on record.
The national average rainfall total of 277 mm in 2019 was the lowest on record, which stretch back to 1900.
With that backdrop of multi-year drought, January's rainfall in Australia provoked a jubilant response from farmers who posted videos on social media of them jumping in puddles and dancing in the rain.
Climate drivers behind dry spell 'beginning to breakdown'
The Bureau of Meteorology said last week the January rainfall was not enough "to overturn the significant long-term rainfall deficiencies being experienced in many regions".
It said however there could be a silver lining with the BoM's January to March outlook pointing to increased odds of "seeing more average rainfall conditions".
"The key climate drivers keeping the continent very dry [are] beginning to breakdown," the bureau said.
Bryce Chapman was one of those jubilant farmers whose video celebrating the January rain was widely viewed and shared on social media.
Posting a video last Thursday, Mr Chapman says he is happy that the rain has returned.
"Hey, what a difference some rain makes. Just have a look at the feed - it is bouncing out of the ground," he said.
"We're still hand-feeding the cattle. But once this feed gets away on us, we'll be able to slow that up. And that is really good news for all the farmers in NSW, and in fact the rest of Australia as well.
"We love this rain. The cows love it. The feed love it. So let's get on with it, and let's end this drought once and for all."