Vanuatu.

What sort of weather could I expect in February in Port Vila?

Webs like Weatherbase are usually useful for this type of questions.

Thanks anillos. Another question -- we have 3 days to spend in Port Vila, apart from visiting the waterfall, what else is there to see on the island? Not interested in snorkeling or bars. Any harbour cruises?

Wet season starts end of November. So... wet would be the answer ;)

February = hot, sticky, rainy and it's overdue for a cyclone here so you never know your luck as Feb is right in the season
Activities:
The 'Coongoola' day cruise is highly rated
'The Summit' Garden Tour is highly rated complete with breathtaking views over Mele Bay and more