May 2015 equalled the coldest May so far recorded here. The month was also the windiest May ever, with rainfall well above average.
The average temperature for May was 10.2°C, equalling the coldest May record set in 2013. The mean temperature for May has now fallen to 11.0°C. This was the third below average month so far in 2015. The maximum temperature was 18.9°C on the 11th at 15:36, this beat the previous year high of 18.4°C set on April 10th by 0.5°C, but was the lowest monthly maximum temperature for May.. The minimum temperature was 1.6°C recorded on the 1st at 02:27. The average daily high was 14.0°C and the average daily low was 6.5°C. The average high temperature was the lowest ever for May, beating the previous low of 14.5°C set in 2015. The overall average high for May is now 15.2°C, with the overall average low being 7.0°C. Sunshine hours were 101.1, well below the average of 116.0, but beating last year’s total by 8.3 hours. On the 26th, the solar UV index of 6.2 surpassed the yearly high of 5.6 set on 21st May by 0.6. This is the highest recorded since July 22nd 2014. A frost has never been recorded in May.
Rain fell on 16 days in the month, with the wettest day being the 3rd when 10.4 millimetres was recorded. The total rainfall for the month was 59.2 millimetres, the second wettest May on record and well above the average of 47.2 millimetres. There has now been 181.8 millimetres of rain in 2015. Evapotranspiration for the month was 89.2 millimetres, 10.1 millimetres higher than 2014.
Wind speeds were the highest ever recorded in May. The average wind speed was 5.8 mph, 1.3 mph higher than average, while the average gust speed was 8.9 mph. The maximum wind speed was 23.0 mph from 225 °(SW) on the 5th at 13:27 and the maximum gust speed was 36.8 mph from 270 °(W) also on the 5th at 11:02, the highest gust speed recorded here in May. The total wind run was 4124.5 miles, with the predominant direction being westerly.
The average barometric pressure for May was 1012.4 millibars, with the highest being 1025.6 millibars at 00:07 on the 17th, and the lowest being 983.7 millibars at 08:38 on the 5th. This was the lowest monthly maximum and the lowest monthly minimum ever recorded in May. The average humidity was 80%.
Weather Underground graph for May 2015.