A close eye's being kept on Wellington's southern coastline as wave swells approach warning levels

A strong wind watch is in place for the capital, with southerly winds potentially reaching severe gale in exposed places this evening.

Five to six metre high waves are also expected in Cook Strait.

MetService meteorologist Tui McInnes says they've given the city council a heads up.

He says it's hard to tell what the effect will be, but it's nearing their warning criteria.