Mark Hunt weather corner; 122 - 2025 joins the record books
2025 is breaking lots of weather records, not least because it represents one of the longest drought periods we have experienced. It also comes hot on the heels, meteorologically speaking, of 2022 and 2018, both very dry and hot years.
What has singled out 2025 as an exceptional year is that the drought started earlier, with both below-average rainfall and above-average evapotranspiration (moisture loss from the plant and soil) occurring from March onwards. The two previous drought years began later. You can see this in the comparison graphs (below) detailing rainfall, E.T. and soil moisture surplus (SMS) / deficit (SMD) from our default location in Thame, Oxfordshire, U.K.
The graphs highlight the deficit in spring rainfall in 2025, higher E.T. levels (vs. previous droughts) and hence an earlier commencement into a soil moisture deficit situation in April 2025. In 2018, we didn’t enter into soil moisture deficit until June and in 2022, May.
In practical terms, this means we have had to potentially irrigate and manage plant stress for a much longer period in 2025.
The other distinct feature of this year’s drought is its geographical distribution. In previous drought years, we have seen the drought most severely affecting the south of England. In 2025, the drought is much more widespread with reservoir levels extremely low in Somerset, Staffordshire, North Wales, Derbyshire, Cumbria, The Pennines and Yorkshire.
Now, could we have predicted that 2025 may be a drought year?
Well here meteorologists are looking at something called ‘Teleconnections’ to help extend their forecast accuracy. Teleconnections, put simply, are relationships between climatic processes great distances apart. Heating and cooling in the Pacific (El Niño and La Niña events) and their relationship with the pressure differential between high and low pressure systems in the Atlantic (NAO – North Atlantic Oscillation Index) are an example of a Teleconnection.
Back in March, I attended an RMets (Royal Meteorological Society) lecture that looked at the relationship between Teleconnections and water resources in the east of England. You can hear it here.
One of the surprising findings (to me) was the strong relationship between La Niña events in the Pacific and drought years in the U.K. Most of the droughts we have experienced in the recent past (1975/76, 1988/92, 1995/96, 2010/2012 for example) have occurred in La Niña years and guess what year we are in this year? Yep, a La Niña year.
So, there’s a hint that by studying Teleconnections we may have more of an understanding of likely rainfall patterns in the future.
I’ll leave you with this thought - if you knew this year was going to be very dry beforehand, what would you have done differently?
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