The country's biggest power generator, Meridian, said recent spring conditions had been "perfect" for renewable electricity generation.
It said after spending the winter recovering from low inflows in early 2025, September saw national hydro storage rise from 79 percent to 110 percent of historical average.
Meridian said its monthly inflows were 181 percent of the historical average in September, lifting Waitaki storage to 91 percent of average.
It said snow storage in the Waitaki catchment - which includes Lake Pūkaki, the country's largest hydro storage lake - was also above average.
Earlier this week, Mercury Energy said it saw record hydro generation in July, driven by heavy rain over the Waikato catchment - with records going back to 1980.
"Winter 2025 wasn't a dry winter in the end, but we have experienced a number of them over the years and we're happy with how things stand heading into summer and with snow melt ahead of us," said Meridian chief executive Mike Roan.
"At the same time, we have seen wholesale electricity prices ease in both the spot market and futures curve."
Roan said the electricity system had become "very good" at managing dry winters.
He praised the government's recent energy package, focusing on near-term firming generation, and the potential import of LNG.
Transpower also released a draft proposal looking to improve generators' access to water in the lower ranges of hydro lakes - known as contingent storage.
"Unblocking access to contingent storage to ensure it's available when needed would improve the security of New Zealand's electricity system in a way that's quicker, cheaper and cleaner than almost any other option out there," Roan said.
