September brings first thunderstorms and rain showers

Thunder had not rumbled in five months before September saw a change in season, with three thunderstorms in the first 10 days of the month, the Met Office said in a statement.

The first showers of the meteorological autumn also hit the Maltese islands in September, yielding 18.4mm of rainfall.

The change in season brought cloudier skies over the Maltese islands, with the two most common cloud types of September being the low-level Cumulus and Stratocumulus clouds. Averaging at 2.4 oktas, the cloud cover for September was slightly lower than the climate norm of 2.6 oktas.

Despite the lower cloud cover, September was not as sunny as expected. Total sunshine hours clocked during the month fell 8.7 hours short of the norm of 254.1 hours.

While September’s sunniest day was bathed in 11.2 hours of sunshine, on the gloomiest day, which fell in the second half of September, the sun shone for a fleeting 0.5 hours.

The month’s air temperature averaged at 26.3°C, surpassing the climate norm by 1.6°C. September’s lowest temperature was recorded on the ninth day at 20.0°C, coinciding with one of the three thunderstorms of the month. The month’s highest temperature of 34°C was reached 10 days later. The sea remained warm, with the average surface temperature losing one degree Celcius over August to stand at a higher-than-average 28.0°C.

September was slightly windier than expected, maintaining an average wind speed of 7.7 knots rather than the norm of 7.1 knots. On September 7 and 11, a maximum gust of 26 knots was recorded blowing from a northeasterly direction on the former day and from the northwest on the latter.