The highest temperature in the month was 25.2°C recorded at 15:39 on the 25th. This was the highest temperature since 25.7°C was recorded on September 14th 2016. The lowest temperature in the month was 2.1°C recorded at 06:32 on the 10th. The average for the month was 12.6°C, 1.3°C above the mean. The average daily high temperature was 17.0°C, 1.5°C above the mean, with the average daily low temperature being 8.6°C, 1.4°C above the mean. Both these daily averages were the highest ever recorded here in May. The warmest day was the 25th with an average temperature of 19.9°C, while the coldest day was the 9th with an average temperature of 7.4°C.
The highest dew point was 19.1°C recorded at 11:53 on the 27th. The lowest dew point was -1.4°C at 18:24 on the 5th, with the average dew point in the month being 9.2°C, 1.7°C above the mean and the highest May average dew point ever. The high wind chill was 25.2°C at 15:39 on the 25th, with the low wind chill being 2.1°C at 06:32 on the 10th. The average wind chill in the month was 12.3°C. There were 209.6 hours of sunshine in the month, with the sunniest day being the 26th with 11.96 hours.
Rainfall in May was 34.2 millimetres, recorded on 12 days. This is 9.6 millimetres below the May average. The wettest day was the 29th when 6.6 millimetres of rain fell. This takes the 2017 total to 143.1 millimetres, 71.2% of the average at the end of May. The highest rain rate was 25.6 millimetres per hour recorded at 22:10 on the 20th.
The highest barometric pressure in the month was 1029.1 millibars recorded at 23:43 on the 8th. The lowest barometric pressure was 994.2 millibars at 06:24 on the 12th. The average pressure for the month was 1015.6 millibars.
Winds in May were lower than average. The average wind speed was 4 mph and the average gust speed 6 mph. The highest wind gust was 29 mph at 17:22 on the 27th and the highest average wind speed was 13 mph at 20:36 on the 27th. The average daily maximum gust speed was 17 mph and the average daily maximum wind speed was 8 mph. The total wind run in the month was 2556.2 miles with the predominant direction being 145°.
The maximum high solar radiation recorded at 12:50 on the 27th was 1215 w/m². The average solar radiation for the month was 185 w/m². The highest U.V. Index was 6.2 at 12:27 on the 28th, the highest since 6.3 was recorded on July 29th 2016.