The ocean's at the altar, but the atmosphere hasn't turned up to the wedding in time for an El Nino spring, says Niwa.
The latest seasonal climate outlook from the National Institute of Water and Atmospheric Research said the chances of an El Nino developing later this year have dropped.
Temperatures between August and October are expected be warmer than usual.
Niwa meteorologist Chris Brandolino said an El Nino was "brewing", but the next few months would be critical to see if all the players fell into line.
He described an El Nino event as a "marriage of the ocean and the atmosphere".
"What we have is the ocean at the altar and the atmosphere hasn't responded. Even if it does happen it will be a weak to moderate El Nino."
The east of the North Island can expect a warmer than average spring, while Waikato should see average or above average spring temperatures, he said.
Cold snaps and frosts could still be expected in some parts of the country as winter moves into spring, he said.
Rainfall totals are each 40 per cent likely to be in the normal or above normal range for Waikato. Soil moisture levels and river flows are about equally likely - a 40 and 35 per cent chance respectively - to be in the near normal or above normal range.
- Waikato Times