Astronomical autumn, which began at 9.21pm on Wednesday, is forecast to be warmer and drier than usual – this is in respect of the reference period from 1981 to 2010. The average temperature in the Balearics is expected to be above normal, which is 15C, while the forecast is for less rainfall than the average of 219 litres per square metre for the three-month period.
Autumn is characterised by Indian summer conditions until mid-November, interspersed with storms that can bring torrential rain. From mid-November, there are more cloudy days and possible frosts in the mountains.
The Aemet met agency reports that summer was very warm, with an average temperature of 24.8C, which was 0.9C higher than usual. In June, the average was 23.1C, which was 1.3 degrees higher than usual. August had the highest average – 26C and one degree above normal. Formentera, with an average of 26.8C, was the warmest island, followed by Mallorca with 24.7C (one degree above normal).
There were two heatwaves. One in July produced a maximum temperature of 41.5C in Montuiri, the highest temperature of the summer. The second, from August 11 to 15, led to a maximum of 41C in Sa Pobla. The highest overnight minimum temperature was 28.9C in Colonia Sant Pere on August 15. There was an increase in the number of tropical nights (no lower than 20C). At Palma Airport, there were 34 tropical nights, when the usual number is 21. At the Portopi weather station in Palma, there were 83 rather than the usual 63.
Generally, the summer was only slightly wetter than usual but with very localised torrential rain. The average was 47 litres per square metre, whereas the normal amount is 39 litres. In Mallorca there were 49 litres, 19% more than usual. There were also twelve days when muddy rain fell in Mallorca; two are what can normally be expected.
The heaviest rain was reserved for the very end of summer, with the Albufera weather station in Muro registering record rainfall of 123 litres per square metre for a 24-hour period starting on September 21.