"That's not too bad," said MetService meteorologist Angus Hines. "But it's a decent amount in an urban area."
The rain doesn't appeared to have caused any damage. Power was restored to 1400 homes in Sunnyvale around 4am this morning.
While the overnight temperature was only in the 20s, it would have felt much hotter, with 80 to 90 per cent humidity turning the city into a sauna - conditions likely to continue next week.
Forecasters say the rain and showers, like the high humidity in northern regions that have foreshadowed them, come from the moisture-laden air directed down over the country by ex-cyclone Winston
"The humid northerly air flow behind ex-cyclone Winston means sub-tropical air that normally lies between Northland and Fiji is now starting to spill down over the nation," says WeatherWatch.
WeatherWatch analyst Philip Duncan said Monday night might be slightly cooler due to a southeasterly change, but that wouldn't last.
The change would push the moist air to the east of the country, only to be pushed back from Tuesday night by an easterly flow and showers.
The forecast for today is showers in Auckland, Coromandel and Bay of Plenty, possibly heavy this afternoon. Northland will be covered by a small, heavy band of rain throughout the day.
The rest of the country is relatively fine, apart from the West Coast and Invercargill.
A day-time high of 27C is forecast for Auckland and parts of Hawkes Bay and Waikato today.
Whangarei is expected to reach 26C and a high of 21C is forecast for Wellington.
Duncan said South Islanders should expect a colder change. Dunedin should see 13C on Tuesday, a huge contrast to Friday's 33C in Christchurch. But in good news, summer conditions should return by mid-week.
"It has been a weird summer," said Duncan. "All the talk of El Nino hasn't happened. It's almost like La Nina, the complete opposite."
Two fronts are coming through in the first and second weeks of March.
"Overall, it encourages more northeasterlies for the top of the country," he said.
The South Island can expect more westerlies and rain on the West Coast.