As Brits, we love to talk about the weather, and the current heatwave is no different. While the UK has historically experienced fairly predictable seasons, it feels as though our summers and winters are becoming more extreme year after year.
Two terms that seem to come up from time to time on the weather forecast is El Niño and La Niña, two climate phenomenons that can strongly influence weather around the world. El Niño and La Niña events occur every two to seven years, on average, but they don’t occur on a regular schedule. forecasts suggest El Niño could become a very strong event by the autumn, lining up with the start of our main flood season. So what exactly is El Niño, and why are meteorologists paying such close attention to it?
What is El Niño?
El Niño is a natural warming of the Pacific Ocean’s surface that happens every few years. It releases huge amounts of stored heat into the atmosphere and shifts weather patterns around the world.
Its effects on the UK are indirect and less certain than in other parts of the world. But the Met Office identifies a consistent pattern: El Niño autumns and early winters in the UK tend to be milder, wetter, and windier, while late winter more often turns colder and calmer.
Haven’t we just had a strong El Niño?
Yes, the last strong El Niño coincided with the winter of 2023/24. England and Wales recorded their wettest period from October to March in more than 250 years. Eleven named storms crossed the UK and many communities experienced flooding.
But El Niño was only part of the story. Scientists found that climate change was one of the main contributors making the heavy rainfall more likely and more intense, due to the warmer atmosphere being able to hold more water, meaning storms release more rain when they arrive.
Why does this matter in the Fens?
Climate change is already making UK winters warmer and wetter. UK winters are now around 1°C warmer and 15% wetter than they were a century ago.
So why does that matter especially in the Fens?
Few places in Britain depend on water management as much as the Fens do. Much of the landscape sits at or below sea level, meaning excess water has to be carefully managed. Keeping it dry relies on a huge network of drains, channels and pumping stations managed by organisations including the Environment Agency, the Middle Level Commissioners and local Internal Drainage Boards.
Most of the time, that system works remarkably well. But extended periods of wet weather place it under greater pressure, especially when heavy rain arrives on ground that is already saturated.
The Environment Agency’s Fens 2100+ programme has been open about the challenge, publishing that much of the Fens pumping and drainage infrastructure was not designed for the rainfall we now experience. A wet autumn running into a wet early winter, with saturated ground, high river levels and high tides arriving together, is exactly the sequence that puts it under most pressure.
Does this mean the Fens will flood this winter?
No. Seasonal forecasts are about probabilities, not predictions. Even a very strong El Niño can produce different outcomes from one year to the next. The next clues will come from updated Met Office forecasts later this summer and autumn. For now, the sensible response is not alarm, but preparedness. While no one can predict exactly what this winter will bring, there are several simple steps you can take now to be better prepared.
What can you do now?
- Check your flood risk. Find out whether your home, or your route to work or school, is in a flood risk area: Check the long term flood risk for an area in England – GOV.UK
- Sign up for free flood warnings. The Environment Agency will alert you by phone, text or email: Get flood warnings by text, phone or email – GOV.UK
- Make a simple household plan. Where would you move valuables? How would you turn off electricity and gas? Who would you check on? Ten minutes now saves hours in an emergency.
- Find out who manages the water near you. In Fenland, this is often an internal drainage board rather than the Environment Agency, and they’re a good first contact about local ditches and drains.
- Ask your town or parish council where emergency rest centres are and whether it has a community emergency or flood plan and offer to help if it doesn’t. Communities with a plan and an up-to-date contact list cope noticeably better when flooding happens.