The James Hutton Institute has reported that last month was the sunniest October recorded at its Invergowrie site since records began in 1954.
A total of 136.8 hours of sunshine was recorded during the month, representing 140% of the long-term average of 97.3 hours. The previous record was set in 1985 with 134 hours of sunshine, followed by 131 hours in 1997. Before that, the only year to exceed 130 hours of October sunshine was 1957.
Despite the exceptional sunshine, temperatures were only slightly above average. The mean temperature for October was 10.0°C, which is 0.5°C above the long-term average. The highest temperature recorded was 18.3°C on 5th October, while the lowest was -0.5°C on 19th October.
Rainfall during the month was slightly below average, with 74.8mm recorded, equivalent to 88.3% of the long-term average. The wettest day was 1st October, when 11.4mm of rain fell.
This will have an impact on this year’s winter crops and, importantly, winter cover crops.
Professor Tim George, Director of the International Barley Hub, explained, “Warm sunny autumns (with adequate water availability) will lead to stronger establishment of winter crops which will potentially enhance their ability to grow well in the spring and improve yield.
“With respect to cover crops, this improved establishment will reduce soil erosion over winter and will enhance their ability to improve soil health. Establishment in the Scottish climate is one of the biggest barriers to reaping the benefits of cover crops.”
There’s an impact on perennial soft fruit crops, such as blueberries and raspberries too. Dr Susan McCallum, Soft Fruit Geneticist and Breeder at the Hutton, said, “The exceptionally sunny October has allowed perennial soft fruit crops to remain active later into the season, continuing to capture sunlight and build energy reserves for the following year.
“However, if mild autumn conditions delay the transition into winter dormancy, crops may become more vulnerable to damage if severe frosts arrive before plants have fully hardened off for winter.”
The long-term averages are based on the 30-year period from 1991 to 2020. It should be noted that the temperature average excludes maximum air temperature readings between September and December 2017 following the removal of mercury thermometers by the Met Office.