How Indian summers became the new normal
Title: “The Shifting Seasons: How Indian Summers Are Redefining the Climate Calendar”
Introduction:
In this era of climate change, our understanding of seasons seems to be in flux. The traditional markers of summer, autumn, winter, and spring are starting to blur, leaving us to question whether September is now becoming a second act of summer, rather than a herald of autumn. Let’s explore this intriguing phenomenon of Indian summers and how they are reshaping our expectations of the changing climate.
The Unusual September Heatwave:
After a wet and cool August that felt more like autumn, the current heatwave across much of the UK has sparked discussions of an Indian summer. With temperatures expected to soar to 32°C in southern England, it’s a stark contrast to what we’d typically expect in September.
Traditionally, if such heat occurred earlier in the year, it might have been labeled a heatwave. Still, meteorologically, we find ourselves in autumn, making this an Indian summer—a term used in English to describe an unseasonably late warm spell. (Although, in some countries, it’s referred to less charmingly as “old women’s season.”)
Is September the New Second Act of Summer?
Given the changing climate, some are pondering whether September will now reliably become a second act of summer, separated from its first part in June or July by a gloomy August. Campaigners even argue for a shift in school holidays to align with this new twin-peak pattern.
Memories of recent Septembers seem to confirm this trend—anecdotally, these late-summer heatwaves are becoming more frequent. Records like the scorching 34.4°C day in Gravesend in mid-September 2016 or the 28.6°C temperature in Charthill in the Scottish borders in 2021 (the highest September temperature north of the border since 1906) seem to suggest a pattern. However, the data presents a mixed picture.
Looking at UK-wide figures from 2015 to 2022, the average temperature in September only exceeded 15°C twice in eight years, with these warm days being short-lived, rather than month-long interludes. Furthermore, the September average temperature consistently falls below that of August, indicating that while the climate may be changing, our expectations aren’t entirely upended.
Regional Differences:
When we delve into regional data, though, we see varying impacts across the UK. For instance, Met Office figures reveal that average September temperatures at Kew Gardens in southwest London have risen from 19.4°C (1961-1990) to 20.3°C (1991-2020).
The Timing of Indian Summers:
Defining when an Indian summer occurs is also a point of debate. Some sources suggest it should extend into deep autumn, with October and November as the true Indian summer season. Certain definitions even require the threat of frost in the air to qualify.
Historically, these late warm spells were named after saints’ feast days in October and November, and some countries still tie their version of an Indian summer to these dates.
Rising Trend in October:
In the UK, there does seem to be a rising trend if we extend our search for Indian summers into October. The past few years have shown an increase in average temperatures for this month, with the figure for 2023 expected to surpass those for July and August, nearly rivaling the warmest day of the year back in June.
A Changing Climate’s Impact:
The reshuffling of warm months in recent years can be attributed to our changing climate. The Met Office predicts that summers will become hotter and drier, potentially reducing the need for Indian summers. Instead, we might find ourselves more concerned about cooler spells.
Conclusion:
The concept of Indian summers is evolving, challenging our traditional understanding of seasons. Climate change is having a noticeable impact on when we experience these late bursts of warmth, and while the pecking order of warm months has been relatively stable in the past, it’s now undergoing a transformation. As we continue to monitor weather patterns, one thing is clear: the changing climate is reshaping the way we experience and perceive our seasons, leaving us with new weather rituals and questions about the future of our climate.