Monthly climate

Climate developments in October 2003

Below average rainfall over much of the Southwest Pacifc

Above average rainfall over parts of Vanuatu and New Caledonia

A region of suppressed convection and generally below average rainfall moved west during October to encompass the Caroline Islands, Nauru, and southern parts of Western Kiribati. Another region of reduced convection moved east, situated over Fiji and Samoa. It was very dry, with 50% or less of average rainfall in parts of Western Kiribati and Fiji. October was the 8th consecutive month with below average rainfall in parts of Eastern Kiribati, and the 4th consecutive month with below average rainfall in parts of Fiji.

The SPCZ extended from the monsoon region (which was relatively weak) to the north of Papua New Guinea, east to Tuvalu, being displaced to the north of its mean location west of the Date Line. There was also SPCZ activity from the Tuamotu Islands of French Polynesia to the region around Pitcairn Island (where rainfall totals exceeded 200 mm). A small region of enhanced convection affected the area north of the equator near the Date Line. The month’s rainfall was at least 125% of average over parts of Vanuatu and New Caledonia, the Kermadec’s, northern New Zealand, and close to or more than 200% of average in the Southern Cook Islands, areas of the Tuamotu Islands, and Pitcairn Island. Rainfall totalling 161 mm was recorded at Rarotonga Airport on the 24th. It was very unsettled at Gambier, Rikitea (southern French Polynesia) with rainfall on at least 25 days during the month.

Air temperatures were at least 0.5°C above average in many tropical Southwest Pacific Islands within a few degrees of the equator, as well as the Marquesas Islands of French Polynesia. It was extremely warm in Samoa, with near average air temperatures on most other islands.

Climate extremes in October 2003