New research has found that Canterbury is not too hot for dairy farming.
A study by Lincoln University says hot weather in summer there is not stressful on dairy cows, as it does not reduce their milk production.
There's been a massive increase in dairying in Canterbury over the past 15 years because of irrigation and it now accounts for almost 15% of dairy herds nationally.
Associate Professor Graham Barrell says the cows studied were able to maintain milk productivity on days when the temperature humidity index was above internationally accepted levels for dairy cows.
He says any variations in production volumes were random and there was no pattern.
He will present his findings to an Australasian dairy science symposium which starts in Christchurch on Tuesday.
The focus is on meeting the challenges of pasture-based dairying.