It won't be much better by hometime, with showers forecast to be heavier and the wind stronger in the afternoon.
Auckland will have fine weather with a chance of a shower shower overnight on Tuesday. Wellington will also be fine but gusting northerlies are forecast for the capital.
Ms Avery said just the west of the North Island and South Island and parts of Southland are likely to have a few showers on Tuesday.
The rain will return to nearly all parts of the country on Wednesday, with the north and east of the North Island remaining fine, Ms Avery said.
Auckland can expect an overcast but dry day on Wednesday, with cloud increasing throughout the day.
Hamilton will be wet with rain increasing in to the evening.
Monday weather:
Auckland: Showers, heavy in the afternoon, 20C
Hamilton: Showers from the afternoon, heavy in the evening, 20C
Wellington: Rain from the afternoon, fresh northerlies, 16C
Christchurch: Rain at times, clears afternoon, fresh northeasterlies, 17C