A Fire Service spokesman said the team were called via 111 shortly after 9pm and had two trucks at the river by the Totara Park bridge in Upper Hutt by 9.26.
"On arrival we found the 4WD stuck in the water, and the river was rapidly rising," he said. "There were two people on top of the vehicle unable to get to the bank."
He said the crew assisted the swift-water rescue team that had been called to the riverbank by police and helped to provide life-jackets and other safety gear to winch the pair to safety.
The spokesman said it took the multi-agency rescue team another 20 minutes to get the pair off the top of the vehicle, with the aid of life-jackets and ropes.
The woman was rescued at 9.51 and the man a few minutes later.
He said they probably had a bit of hypothermia and were being treated by ambulance staff.
The Fire Service spokesman said there had been solid rain in the Wellington region which could give rise to higher river levels and surging currents.
Police said they'd be talking to the pair about what happened.
Meanwhile, further south, heavy rain also caused some floods to close roads and a creek to burst its banks on the West Coast.
State Highway 63 was closed due to the flooding from the overflowing creek between Hector and Mokihinui.
The highway between Karamea and Granity was also closed.
Police said there was no indication yet as to when the roads would reopen.
MetService forecast indicated the rain was set to continue for the next few days on the West Coast, but was expected to ease in the capital today.
