New data has revealed just how hot and dry it’s been so far this summer, in stark contrast to last year.

Of course, hot summer days aren’t uncommon, but the combination of very hot days and muggy nights this January were.

In Auckland, daytime temperatures ranged between 27°C-30°C and overnight not dropping below 20°C or 21°C.

Wellington set a new January record with 29.6°C, and Whanganui broke its warmest ever January overnight temperature with 21°C.

Northwesterly winds drove the mercury up in the east, with temperatures of 33.7°C and 33.4°C recorded in Christchurch and Hastings respectively.

It wasn’t all heat this month though.

Toward the end of the month, Queenstown saw the biggest temperature swing, with Monday’s high of 24.2°C dropping to a low of just 2.8°C on Wednesday.

Watch 1News weather presenter Erin Conroy break it all down in the video above.