September 2026 was one of the warmest on record for the Isle of Man, but the month was characterised by frequent rain, cloudy skies and persistent southwesterly winds.

The mean 24-hour temperature recorded at Ronaldsway was 15.3°C, which was 1.4°C above the climatological average.

That made September the joint third warmest on record, alongside September 2021, and just 0.2°C below the record set in 2023.

The warmth was particularly noticeable overnight, with a mean minimum temperature of 13.1°C – 1.8°C above average and the second warmest recorded for September.

Despite the high overall temperatures, the month's highest temperature was a relatively modest 20.3°C.

Rainfall was also above average, with 89mm recorded at Ronaldsway compared with the September average of 69.9mm.

There were 20 days on which rain was recorded, compared with an average of 14.9 days, while 16 were classified as wet days against an average of 10.8.

The rainfall was spread throughout the month rather than being dominated by a single exceptional event, with several significant spells contributing to the above-average total.

Sunshine levels were below normal, with 121.4 hours recorded during September – around 15% below the climatological average of 142.6 hours.

Wind speeds were also higher than average.

The mean wind speed was 13.1 knots, 1.8 knots above the climatological average, with nine days of strong winds recorded.

There were no gales during the month, although the highest hourly mean wind speed reached 29 knots and the highest gust was 44 knots.

A spokesperson from the Met Office at Ronaldsway added: ‘The combination of mild temperatures, below-average sunshine, frequent high cloud cover, above-average rainfall, and persistent southwesterly winds produced a month that was warm without being dominated by hot settled weather.’