Christchurch has received just 5.2 millimetres of rain through May 2026, against a May average of approximately 56mm and a previous record low of 11.2mm set in 2012. With only a few days of the month remaining, the city appears almost certain to set a new record for its driest May since reliable rainfall records began.
The dry spell is driven by an unusually persistent high-pressure ridge that has held over the South Island through most of autumn. MetService meteorologists note that while dry Mays are not unprecedented in Christchurch — the city sits in the rain shadow of the Southern Alps and can swing significantly between wet and dry autumns depending on the dominant wind direction — the blocking pattern this year has been exceptionally stable.
The east of the South Island and the lower North Island have been the driest regions nationally, with other parts of the country experiencing closer-to-average conditions. MetService forecast some showers for the weekend of 30 May and possible light rain early the following week, but analysts said even a moderate rainfall event was unlikely to prevent the record from falling.
The extended dry conditions have been a talking point for Canterbury farmers and water managers. Irrigation demand across the Canterbury Plains remained elevated well into autumn, and some groundwater and river levels are tracking below seasonal norms.
NIWA is expected to formally confirm whether the record falls once final rainfall figures for May are compiled. A handful of historical dry seasons — including 1972, 1996, and 2012 — have shown similar blocking high patterns, but the 2026 system has been noted for its longevity and consistency.
Looking ahead, MetService's extended forecasts for June suggest a return to more typical winter westerlies, which historically bring regular frontal systems and rain to Canterbury. The ski fields, meanwhile, welcomed the cold temperatures accompanying the high pressure, with snow accumulating on the ranges above Christchurch even as the city below stayed dry.
"Christchurch has received only 5.2mm of rain so far this month, compared to 76mm last year in May." — MetService / ODT Star News, 28 May 2026
