An adventurer attempting to paddle across the Tasman is expected to pull into New Plymouth on New Zealand's east coast in less than three weeks time.

43-year old Scott Donaldson set off on his two thousand kilometre solo paddle from Coffs Harbour on April the 19th, planning to take 70 days to reach New Zealand.

He is now 47 days into the trip after his water desalinator broke in early May, forcing him to make landfall at Lord Howe Island.

Consulting meteorologist Bob McDavitt said Donaldson is heading into an interesting part of the trip - with some difficult weather on the way.

He said the arrival of winter will see temperatures fall.

"The southerlies coming straight off the Southern Ocean are very cold, air temperatures are dropping down to about 5-6 degrees at night," he said.

"But he's in the sea itself, very close to the ocean, and that's tempering his actual temperatures in the kayak, keeping them at around 10-15 degrees within the kayak."

Mr McDavitt said the weather may still turn, but has been fairly favourable up to this point.

"It's not as fast as I suppose it could be, we've had one or two setbacks, he had to do a couple of backward loops because of the weather conditions or the currents," he said.

"But I'm very happy with the progress, it's going forward in the right direction."