Property Brokers regional manager Guy Mordaunt said inquiries were solid for rentals in Carterton and there was a lack of houses in the area.
He said Greytown would also attract a lot more renters if more properties were available.
Mr Mordaunt said rents didn't tend to get too high in Wairarapa, because those who could pay high rents could usually afford to buy their own home. He said rents were increasing in line with inflation and he expected year-on-year rent rises to remain consistent.
Trade Me property head Nigel Jeffries said the national median asking rent went from $420 to $435 between December and January.
This was in stark contrast to the rest of 2015, which showed very slow growth. Mr Jeffries said the January rent correction occurred each year, as many landlords adjusted their rents at the beginning of the year.
Rents in Auckland were up $5 a week to $500.
Excluding Auckland, the typical median asking rent around the country jumped $15 a week from $370 in December, to $385 in January.