Westerly winds will prevail over the country on Monday, creating quite a contrast between the showery, wet, west and dry, sunny, east. In fact in the South Island rain will be persistent rain along the western side for the rest of today. The amount is not likely to be too high nor will it be too heavy.
In contrast, the eastern side of New Zealand will be mainly dry and warmer than usual because of the northwesterly winds across the Southern Alps and eastern North Island ranges. The South Island has the highest wind speeds, around 40 km/h through the Canterbury interior during Monday night.
From Tuesday to Wednesday, most areas will be sunny and warm, except Northland where showers are likely.