Warm and sunny September

  • Half the amount of thundery days than anticipated for September
  • A total rainfall of 16.4mm was recorded, a third of what was expected
  • September was warmer, sunnier and winder than usual

Temperatures last September rose higher than the norm with an average of 25.9˚C, 1.2˚C hotter than usual. 19 days felt warmer, with the temperature on the last 9 days of the month dipping and allowing Malta a break from the heat. The last day of the month was also the coldest day in September at 17.8˚C, while the temperature peaked at 36˚C on the 19th. September nights were warmer than expected by 1.1 ˚C, with the average temperature varying between 21.9 ˚C and 29.9 ˚C, the highest of which exceeded the climate norm of 28.5˚C. The sea temperature reached an average of 26.7 ˚C, higher than the expected norm of 25.5 ˚C and second highest since 1977. The warmestseatemperature for September on record was measured in 1999 with an average of 26.7 ˚C.

The warmest September days occurred on the 9th and 10th of 1924, with temperatures rising to 38.9˚C.

Less than a third of the expected rainfall fell on the Maltese islands last month, with 16.4mm of rainfall,falling short of the expected norm of 58.1mm for this time of the year. The driest September on record in 1943 saw no rain, while September 1997 suffered a deluge with 266.9mm documented.

Only two thundery days occurred last month on the 8th and 9th, which is half the climate norm of 4 days – no fog or hail were experienced on any day. The stormiest September ever recorded was in 1955 with 11 days of thunder, followed by 10 days in September 2003. A mean relative humidity of 70% was measured last month, which is lower than the climate norm of 75%.

September was slightly windier than the norm of 7.1 knots, with 7.6 knots documented on average. Light winds in the 1-10 knots bracket blew over the islands 79% of the time, with variable winds blowing 5% of the time. The winds helmed most frequently from the Northwest, the predominant wind direction for the Maltese islands. Winds were stronger than 34 knots on three days; the 19th with 35 knots, the 21st with 39 knots, and the strongest winds on the 20th at 43 knots.

September was also sunnier than expected with 9.23 hours of sunshine every day, over 45 minutes of added sunshine when compared to the climate norm of 8.5 hours. The brightest day last month was on the 2ndwith 11.8 hours of sunshine, while the dullest day occurred on the 25thwith only 1.2 hours of sunshine. An average cloud cover of 2.3 oktas was documented last month, which was lower than the norm of 2.6 oktas. In total, 276.9 hours of sunshine were noted in September, which is higher than the norm of 254.1 hours.