New Zealand is a long country, ranging from 37 degrees latitude in the far north to 47 degrees latitude in the far south. It is not surprising that we have very different weather in different parts of the country.
More North Westerly winds affected the North Island bring warmer temperatures but more South Easterly winds affected the South Island, bringing cold temperatures.
Auckland was the warmest main city with an average temperature of 13.3 degrees Celsius whereas Christchurch was the coldest main city with an average temperature of 9.3 degrees. Auckland had 261 mm of rain which is 3 times the normal rainfall. It was also a record for May. On the other hand, Christchurch was the driest main city with 70mm of rain in the month.
In contrast, both islands felt the cold southerly blast from Antarctica on May 27th, bringing snow to main roads near the central mountains in the North Island and to mountain passes in the South Island.
Note: The mean (average) temperature for one day is calculated by adding the lowest and highest daily temperatures and dividing by 2. Add all these for the month and divide by 31 for the mean temperature for the month.
Pronunciation
Note south (rhymes with mouth) but southerly (rhymes with motherly)
Comparing
Note spelling: wet, wettest; dry, driest
Note this phrase: 3 times the normal rainfall
Words and phrases for comparing: but, whereas, on the other hand, in contrast