Of the four main cities Christchurch has the least rainfall and the greatest range of temperature. Rainfall averages 26 in. per annum and falls on 129 days, including 62 days with at least 0.1 in. Rainfall is fairly evenly spread through the year, but is slightly lower in the period February to April, and also in the spring, than at other times. Once in 20 years a fall of 3.9 in. can be expected within 24 hours and 0.7 in. in one hour.

Highest temperatures are assöciated with the “Canterbury Nor'wester” which is a typical fohn wind, strong, gusty, and very dry. In summer it raises temperatures above 80°F and occasionally above 90°F, while relative humidity drops to 20 per cent or even less. Christchurch, on the average, has 17 days with temperature rising over 80°F. At the other extreme, it experiences 37 screen frosts and 90 ground frosts per annum, chiefly between April and October. The warmest month is January, with a mean temperature of 62°F and a mean daily maximum of 70°F and a mean daily minimum of 53°F. In July the mean is 42°F and the mean daily range extends from 50°F to 34°F. Sunshine averages 2,000 hours per annum, each month receiving about 45 per cent of the possible sunshine, except December which has only 41 per cent.

North-easterlies are the prevailing winds, but south-westerlies are almost as frequent. These are relatively cool winds and the north-easterlies at times bring low cloud or fog in over the city. Fog due to various causes is reported on 23 days per annum, chiefly between April and August. In winter, fog occasionally persists throughout the day, but most of the fogs clear within a few hours after sunrise.

Snowfalls are light and infrequent, though heavy falls have been known. On 14 July 1945 the depth of snow was about 1 ft over most of the city. This was the heaviest snowfall on record, with the possible exception of one in July 1867. Hail is reported on six days per annum and on very rare occasions has caused local damage to glasshouses and gardens in the district. Thunder is heard on about four days a year, chiefly in the summer.