An historical perspective of the climate statistics
for Coventry during September 2024
Temperature
In the first decade of the 21st century, the average monthly September temperature was 14.9°C, indicative of recent warming, compared to the warmest decade of the 20th Century, in the 1980s at 14.2C.
After the warmest September in over 132 years in 2023 (17.2C), September 2024 (14.4C) saw mean monthly temperatures edge back closer to normal, 0.1C below the 30-year average for Coventry (1991-2020).
It was the coolest September in the city since 2018 (14.3C); only 7 September months have been cooler than 2024 since the Millennium (2007, 2008, 2010, 2012, 2013, 2015, 2018).
There were three grass frosts during the month, the most in any September in Coventry since 1979, when there were six.
Just out of interest, there hasn’t been a September air frost in the city since 1919.
Rainfall
During the first 20 years of the 21st century, September rainfall averaged 49.0mm, compared to 76.1mm in the decade 1991-2000, suggesting a considerable drying trend in this first autumn month of the season in Coventry.
After a dry August, in which only 21.6mm of rain was recorded at Bablake, the first three weeks of September was also quite dry with just 24.6mm of rain by the 20th day of the month.
There then followed a spell of exceptionally heavy rain from the Equinox with well over 100mm of rain recorded by month’s end, 82% of the whole month total.
So with 133.8mm of rain (231% of average), September 2024 became the wettest September in Coventry since 1883 (139.8mm). Only Septembers 1879 and 1883 have been wetter than this year since 1870.
Sunshine
Thanks to the Clean Air Acts of the last century, September sunshine totals in Coventry had increased by 20% during the 20th century, with an average of 128.3hr per month from 1901 to 2000.
This trend has continued since the Millennium in Coventry, with a further 10% increase from 2001 to 2020 (141.3hr).
With just 111.3 hours of sunshine (81% of average), September 2024 has become the dullest September since 2008 (110.2hr).
Only three September months have recorded fewer sunshine hours in the past 30 year (2000, 2001 and 2008).
***As a footnote, this was the windiest September in Coventry (6.8mph) since 2011 (7.0mph).***