May 2012 was warmer than usual. The mean temperature of the month was 27.0 degrees, 1.1 degrees above the normal figure of 25.9 degrees. The early part of the month was exceptionally warm. With the prevalence of warm maritime airstream together with abundant sunshine, the mean temperature rose to 27.7 degrees during 1 to 15 May and tied with that of 1977 as the highest in the first half of May since record began. Moreover, the lowest temperature of the month as recorded on 5 May was 24.1 degrees, the highest absolute minimum temperature for May on record.
The monthly total rainfall was 277.7 millimetres, about 9 percent below normal. About 70 percent of the monthly total rainfall was associated with the heavy rain episodes in the latter half of May. The accumulated rainfall since 1 January was 666.3 millimetres, slightly above the normal figure of 640.7 millimetres for the same period.