There are weather stations around the Canterbury area. Below are some useful links.
Diamond Harbour Click Here
Chateris Bay Click Here
Lyttelton
for the Lyttelton Port Company current conditions and forecast Click here
alternatively for 'Weather Underground' Click Here
Port Levy Click Here
Also a great website/app PredictWind, free version gives forecast to 8km radius, updated hourly.
Gives very delailed information that can be more precise than Metservice. Create a log-in and use the app on your Cell Phone Click here
Three more sites -
Metservice https://www.metservice.com/national/home
Metservice marine Click here
Windy.com https://www.windy.com/?-42.220,165.372,7