It was very windy today, with the newly recalibrated anemometer registering gusts over 40 knots (one of the criteria for a gale warning) while the average wind speed for the day was 13.9 knots or Beaufort 4 (a moderate breeze). There were short periods where the average wind speed reached Beaufort 6: a strong breeze.
We have strong winds in August quite often as the first autumn storms come in from the Atlantic. These cyclones form where arctic air meets tropical air out over the ocean. The warm air rises over the cold, and the rotation of the earth causes the meeting of the two air masses to spin, on a vast scale of many hundreds of miles. The rising of the warm air causes pressure to drop, so air moves in around the circulation and winds build. During "high summer", arctic air and tropical air may be rather similar in temperature and humidity, and it is the difference that drives the power of any Atlantic Storm. As we move towards autumn, and then winter, the contrasts, and so the storms, tend to grow.