Monthly summary September 2011

September 2011 was the warmest for four years and the fourth warmest September I have recorded. The mean temperature of 15.0°C was 1.2°C above the long-term average. The month ended with a mini-heat wave when the thermometer peaked at 26.6°C on the 29th and just lower than this on the following day with 26.4°C. This was brought about by a large high pressure area to the east of us allowing very warm and dry air to flow north from the Mediterranean. This system became a blocking high stopping weather fronts from making progress from the Atlantic. A record was set for this station on the 10th when the minimum temperature was a very warm 16.4°C., which was warmer than three of the day time temperatures in the month. It was also a relatively dry month; the total of 46.9mm was 74% of the long-term average. After a warm start for the first two days we had nine successive days of rainfall, but no great daily totals. The wettest day was the 18th with 8.1mm.

Leave a Reply