Current Climate - January 2011

In January 2011 much lower-than-usual pressures affected the region north of New Zealand, resulting in more easterly winds than normal over the country. During the month, three lows of tropical origin brought torrential rain and gales; former tropical cyclones Vania and Zelia produced heavy rain on the 18th on the West Coast, resulting in the Fox River bursting its banks. A low of tropical origin (which formed near New Caledonia) moved towards New Zealand on January 22/23, producing extremely heavy rainfall, flooding, slips and road closures over much of the North Island, north of about Wanganui. Also, Tropical Cyclone Wilma moved rapidly across the northeastern North Island on the 28th/29th, causing widespread deluge rainfalls, severe flooding and slips, in northeastern regions of the North Island.

Rainfall

Rainfall totals were about four times (400 percent of) January normal in eastern Northland and Auckland, the Firth of Thames, Coromandel and western Bay of Plenty - with many new records set - and at least double (200 percent of) January normal over the rest of the North Island (the exceptions were Wellington, the Kapiti Coast and parts of the Manawatu, which recorded between 120 and 150 percent of normal).  January rainfall totals were also above normal (more than 120 percent of normal) for Westland, the Kaikoura Coast and parts of Southland and Otago.  In contrast, it was a rather dry month for parts of inland south Canterbury and the Nelson Ranges (which recorded less than 50 percent of normal).  Elsewhere, January 2011 rainfall totals were closer to January normal (between 80 and 120 percent of normal).

Air temperature

Mean monthly temperatures for January 2011 were well above average (at least 1.2 °C above average) in parts of Northland, Auckland, Waikato, and Bay of Plenty, and above average (between 0.5 °C  and 1.2 °C above average) across much of the remainder of the North Island, as well as for coastal Westland and Fiordland.  Temperatures were near average (within 0.5 °C of average) over much of the South Island, as well as in Wellington, Wairarapa and Hawkes Bay.  The New Zealand national average temperature was 17.4°C (0.3°C above the 1971–2000 January average). 

Sunshine

Sunshine totals in Coromandel, Bay of Plenty, Gisborne, Wellington, Wairarapa and Marlborough were below normal (between 75 and 90 percent of January normal), showing the effect of the prevailing easterly winds during the month. In contrast, it was very sunny in south Canterbury with well above normal sunshine totals (more than 125 percent).  Sunshine totals in Taranaki and the Ruapehu District were also above normal (between 110 and 125 percent of normal).  Elsewhere, January sunshine totals were near normal.

See our January 2011 climate summary

click here to subscribe to the Climate Update e-mail list.