Weather

MetService meteorologist Michael Pawley says Lake Tekapo recorded New Zealand's coldest night of the year so far, with the air temperature dropping to minus 12.5C in the early hours of Sunday.

A low-pressure system arriving late Tuesday is forecast to bring up to 200mm of rain, severe gales and a sharp temperature drop across much of the country.

Forecasts are easier to use when you understand the systems behind them. A plain-language guide.