Weather review – January 2015

January 2015 was slightly warmer and sunnier than average. Rainfall was less than normal but the month was the windiest January ever recorded here.

Mild temperatures heralded the start of 2015 with a temperature of 11.9°C on New Year’s Day, the highest ever recorded here. The highest ever January temperature was also set at 17:37 on the 9th when the thermometer reached 14.0°C. This beat the previous best of 13.3°C recorded at 16:31 on January 29th 2013. The minimum temperature in the month was -3.1°C at 06:50 on the 19th. The last time a lower temperature was recorded was March 14th 2013 when the low was -3.7°C. On the 21st, the maximum temperature of 1.3°C, recorded at 08:37, was the lowest daily maximum temperature since 0.2°C was recorded on March 24th 2013. On the 28th, the temperature fell from 8.6°C at 09:33 to 3.7°C at 10:00, a fall of 4.9°C in 27 minutes. This was the result of a cold front, and low pressure system passing to the north of the country. The average temperature for the month was 3.8°C, 0.2°C above the mean for the month. The average daily high temperature was 7.0°C, 0.9°C above the mean, with the average low temperature being 1.0°C, 0.1°C below the mean. This was the fifth successive month of above average temperatures. January was sunnier than normal with 65.7 hours recorded, this was well above the 58.5 hours recorded in 2014. The average dew point was 2.2°C.

The most notable weather event in the month was the wind strength. On the 10th, the high wind gust speed of 49.5 mph surpassed the all time high of 48.3 mph set on December 5th 2013 by 1.2 mph. The maximum sustained wind speed of 31.1 mph from 270° (W) at 06:24 was the highest ever recorded here in January. This beat the previous highest of 28.8 mph, recorded on January 22nd 2012. The average wind speed was 6.7 mph and the average gust speed was 9.9 mph, both January records. The average maximum wind speed was 24.0 mph, also a January record and the highest since February 2014.

Rainfall and other precipitation totalled 38.8 millimetres, 4.1 millimetres below the January average. Precipitation was noted on 24 days, with the wettest being the 15th when 7.2 millimetres was recorded. There was 9.3 centimetres of snow recorded on seven days with the first snowfall of 2015 occuring on the 18th. The heaviest snowfall was on the 30th when 4.0 centimetres was measured. Evapotranspiration for the month was 17.8 millimetres, 5.7 millimetres more than 2014, and the highest since October 2014.

The maximum barometric pressure was 1035.1 millibars on the 4th at 11:30. The low barometer of 973.7 millibars, recorded on the 30th at 02:58, surpassed the January record low of 978.3 milliibars recorded at 19:35 on January 1st 2014. The average pressure for the month was 1010.5 millibars. The average humidity was 89%.

Weather Underground chart for January 2015.