December was a remarkable month in which, for the first time, the temperature never dropped below 0°C. Apart from being extremely mild, it was a very windy month, with the highest gust speed record broken, while rainfall was well down on the average. A new barometric pressure low was also set in the month.
The average temperature in the month was 5.8°C, compared to the mean of 3.6°C. The highest temperature was 12.8°C recorded on the 16th at 06:39, with the lowest being 0.0°C at 00:20 on the 20th. This was the highest minimum temperature and the highest average temperature in December. The coldest daytime temperature was 5.6°C on Christmas Day. There were 58.7 sunshine hours in the month, compared to 54.2 hours in 2012. The maximum heat index was 12.8°C on the 16th at 06:39, and the maximum dew-point was 11.7°C on the 15th at 22:46. The lowest dew-point was -1.8°C on the 6th at 01:31, with the average being 4.1°C. This was the highest maximum dew-point in December. The average daily maximum temperature was 8.6°C and the average daily minimum temperature was 2.9°C. There were no (air) frost days.
Another feature of the month was the strength of the winds. Although the average wind speed of 6.1 mph, and the average gust speed of 9.5 mph, weren’t records, the maximum wind speed and maximum gust speed records were broken. The new record maximum wind speed is 33.4 mph from 338° (NNW) on the 5th at 13:44 and the maximum gust speed record is now 47.2 mph from 315° (NW) also on the 5th, at 10:14. The maximum gust speed beat the previous high by 0.1 mph, set in February 2011. The mean speed for the month is now 4.8 mph, making December the windiest month in the year. The total wind run was 4,565 miles, compared to the average of 3,594 miles.
Rainfall totals for the month were 33.6 millimetres, well down on the average of 53.4 millimetres. Rain fell on 21 days, with the wettest day being the 18th when 5.6 millimetres was recorded. No snow has been recorded in the season so far. Evapotranspiration for the month was 15.6 millimetres, compared to 10.2 millimetres in 2012.
The average barometric pressure for the month was 1010.7 millibars, with the maximum being 1035.9 millibars recorded on the 2nd at 00:52. The minimum barometric pressure of 966.6 millibars recorded at 00:19 on the 24th was a station record, beating the previous record low of 966.9 set in November 2010.
Related articles
- Weather review – November 2013 (alanrowley.info)
- The Highest Wind Speed Recorded (weather.answers.com)
- The wettest Christmas since … 2012 (smh.com.au)
- What Does the Weather-Related Term Dew Point Mean? (geography.answers.com)
- Understanding the Importance of the Dew Point Definition (weather.answers.com)
