A WARMER AND DRIER SEPTEMBER BRINGS SUMMER TO A CLOSE

  • Highest temperature of 35.7°C reached in July; lowest of 18.1°C recorded in September
  • Over 223 hours of sunshine recorded in September
  • September contributes 4.1 mm of precipitation to the season’s total of 70 mm

A September that was warmer than the 30-year climate norm brought summer 2018 to a close. Air temperatures for the season varied between a lowest minimum of 18.1˚C recorded in September and a highest maximum of 35.7˚C recorded in July.

Summer days were brightened by a good amount of sunshine, with each month enjoying the sun for an average of 305.5 hours. While July was the brightest summer month, treating islanders to 363.6 hours of sunshine, with 223.5 sunshine hours recorded, September was the dullest. Last month was also duller than the climate norm, falling 30.6 sunshine hours short of the quota for this time of year. A heavier-than-usual mean cloud cover of 3.3 oktas can partly explain this shortage.

Rain too was in short supply in September, with the month producing a mere 4.1 mm of precipitation as opposed to the norm of 58.1 mm. However, last month was still wetter than September 1943, which holds the record for the driest September with no rain whatsoever measured. Precipitation for the whole season amounted to 70 mm, with around 76% of this total being collected in August, making it summer’s wettest month.

Meteorological records show that throughout summer, thunder was heard on 10 days. Two of these thunder occurrences were observed in June, three were observed in September, and five were observed in August. Despite the rain and the thunder, August was the calmest summer month, with the wind speed averaging at 6.9 knots. On the other hand, the windiest month was June, with wind speed blowing up to an average of 9.4 knots.

SUMMER AT A GLANCE

PARAMETER MEASUREMENT
PRECIPITATION 70 mm
MEAN AIR TEMPERATURE 26.0˚C
THUNDERY DAYS 10
FOGGY DAYS 4
MEAN SUNSHINE HOURS 305.5 hours