MONTHLY CLIMATE SUMMARY - ACT METEOROLOGICAL OFFICE

December significantly dry and windy in ACT

At Canberra airport, only 15.2 millimetres of rain was recorded over six days, compared with the December average of 53.5mm over eight days. This puts December 2001 below the 2nd decile level (the driest 20 per cent level) for all Decembers on record. Most rain fell in the first week of the month, with dry and warm conditions for the last half of December. There were three thunderstorm days for the month (average four). The dry conditions were experienced across the whole of the ACT, with totals ranging from 6.2mm at Hall to 19.0mm at Lanyon.

The December mean daily maximum temperature of 26.8 degrees Celsius was above the average of 25.9 degrees, while the mean daily minimum temperature of 11.2 degrees was marginally below the average of 11.3 degrees. There were eight days of 30 degrees or more for the month, one more than normal. There were no days of 35 degrees or more (average one day). There was one frost for the month (27th) (average 0). This was only the seventh occasion that a frost was recorded at the airport during the week after Christmas. The minimum temperature of 1.7 degrees on the 27th was the coldest December morning for 37 years. The record minimum temperature of 1.1 degrees was set on 18 December 1964.

The mean daily temperature (average of the daily maximum and minimum temperatures) of 19.0 degrees was just above the long-term figure of 18.6 degrees. Although conditions were warmer and drier than normal, the mean daily sunshine of 9.8 hours a day was only just above the long-term average of 9.4 hours.

December was also windier than normal, with a mean daily wind run of 233.5 kilometres a day (average 205.8 km/day). There were also four days of strong winds - two days above average. The strongest wind gust for the month of 76 km/h was recorded on Christmas day. The dry and windy conditions also resulted in evaporation being above average. Overall evaporation was 274.8mm compared with the average of 251.1mm.

No fogs were recorded for the month, which is usual. The average daily pressure of 1007.0 hectopascals was well below the mean value of 1011.4 hPa.

Summary for Canberra airport - December 2001
Mean maximum temperature	26.8 degrees (av 25.9 degrees)
Highest maximum temperature	34.8 degrees (20th)
Lowest maximum temperature	18.7 degrees (8th)
Mean minimum temperature	11.2 degrees (av 11.3 degrees)
Highest minimum temperature	15.4 degrees (15th)
Lowest minimum temperature	1.7 degrees (27th)
Lowest grass temperature	minus 2.7degrees (27th)
Total monthly rainfall	15.2 mm (av 53.1 mm)
Total monthly evaporation	274.8 mm (av 251.1 mm)
Mean daily sunshine	9.8 hours/day (av 9.4 hours/day)
Mean daily pressure	1007.0 hPa (av 1011.4. hPa)
Mean daily windrun (at 2 metres)	233.5 km (av 205.8 km)