Going by Data sent in by New Zealand Local Weather Forum stations
for 16/7/21.
Warmest night=Pakawau 13.6C
Coldest night=Wanaka -0.4C
Warmest day=Ohauiti 22.4C
Coldest day=Castle Hill 8C
A.v.g air temp for the 24 hours 11.61C
WETTEST=Arthur's Pass 205MM
WINDEST= Arthur's Pass 82.1KM