Parched December 2009 went soggy

The daily weather log

Weather log December 2009

December began dry, very warm, and almost cloudless. In all, there were fourteen days over 35°: remarkable except that it had happened in November too! Plants began dying from lack of rain and low humidity. By the 19th there had been 39 days without 5 mm of rain. The Dew Point on the 12th (-1.1°) was the lowest for a December morning.
Within a week, the sky became overcast, the days cool, and the humidity extreme: the Dew Point from the 27th on was near or above 20°. The hills were often hidden in cloud or rain. The highest rainfall reading (44.6 mm) is a total of several rain days. Heavy rain fell during Sunday the 27th.

 Comparing December months

Climate December 2009

The mean maximum temperature (33.1°) is not as high as in December 2005 (33.7°), but the mean mean (25.9°) and mean minimum (18.6°) are the highest for the decade. All are two degrees warmer than normal, but not extreme as in November.
At 52% cloudy mornings this month was very cloudy, but not as cloudy as December 2007 (58%). The mean morning Dew Point, 12.6°, was normal.
The rainfall total of 75.6 mm is in the 55th percentile, just above the median for December. Most totals for more than one month are quite good. Shortages affect the 6-, 9-, and 12-month totals, but even the 9-month total (now 334 mm) is no longer a serious shortage: it is in the 13th percentile. A shortage in the 10-year rainfall total (15th percentile) may be keeping river base-flows and deep water tables down.

The year 2009

The year 2009 was dry, with only 495 mm of rain. That is on the 16th percentile, meaning one year in six has been drier. It followed two wet years, 2007 with 741 mm (68th percentile) and 2008 with 720 mm (64th percentile).

Data. Rainfall data is from Manilla Post Office, courtesy of Phil Pinch. Temperature and other data are from 3 Monash Street, Manilla.


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