The Link Between El Niño and the UK Weather? Are we Scheduled for a Stormy Winter Ahead?

The likelihood of a severe weather system hitting the UK can happen at any time of the year, but the autumn months are consistently one of the most active periods for storms and subsequent flooding.

There are several reasons for this increased likelihood during autumn, most noticeably the shifting jet stream patterns and warmer Atlantic seas which still retain their heat from the summer months. The combination of both allows for strong storms to roll in from the Mid-Atlantic towards the UK.
However, a lesser-known weather phenomenon known as the El Niño, can also have a strong impact on the UK weather.

What is the El Niño?

The El Niño is associated with the El Niño Southern Oscillation (ENSO), which is where unusually warm sea surface temperatures occur within the central and eastern equatorial Pacific. These temperature variations occur every 2 to 7 years and last between 9 to 12 months on average, with an El Niño phase being declared when the sea temperatures rise by 0.5 °C above the long-term average for the region of the central and eastern Pacific.

The other major phase of the ENSO is the La Niña phase, which is the contrasting side of the fluctuation whereby sea surface temperatures cool. Between each phase there is a neutral state where sea temperatures in the Pacific are at their average expected temperatures.

The warmer sea surface conditions which are associated with the El Niño phase can influence global atmospheric circulations, such as the Walker Circulation, which can subsequently impact weather patterns in locations thousands of miles away like the UK.

The effects of an El Niño phase for the UK and Europe typically brings:

• Summer months (June – August) – Warmer and drier conditions during summer months;

• Start of winter (November – December) – Milder and wetter conditions, characterised by western winds from the Atlantic;

• Later winter (January – March) – Increased chance of colder spells.

• Storms and rainfall – Higher likelihood of windy and wet spells, particularly in early winter.

How has the El Niño historically impacted the UK?

The effects of an El Niño phase can be a cause for concern for the UK, as warmer temperatures and wetter conditions can result in strong storm systems.
In 2015-2016, the UK experienced the wettest and warmest December on record for at the time, which also correlated with a strong El Niño phase. In December 2015, Storm Desmond swept across the UK which brought severe flooding, particularly across Cumbria which experienced over 340mm of rain within a 24 hour period. Storm Desmond was linked to an unusually strong jet stream and mild atmospheric conditions for the time of year, which was possibly influenced by a strong El Niño phase.

Then again in October 2023, Storm Babet caused significant flooding across the UK, which also correlated with the 2023 El Niño which was among the five strongest on record according to the World Meteorological Organisation.

However, there are a number of climatic factors which govern the UK weather. The UK weather is not subjected entirely to El Niño phases, as other dynamics such the North Atlantic Oscillation (NAO) and the Quasi-Biennial Oscillation (QBO) have strong impacts. Nonetheless, evidence and data do suggest El Niño phases may have a noticeable impact.

When was the last El Niño cycle?

We are currently in an El Niño phase right now.
The latest El Niño phase began developing back in late 2023 and peaked around January 2024 according to the World Meteorological Organisation. Average sea surface temperatures were approximately +2.0°C above the 1991-2020 average in parts of the eastern Pacific.
However, it is understood that the El Niño phase has been weakening since 2024.

Despite the weakening of the current El Niño, its impacts can still be felt globally. Recent research conducted by the Met Office and partners has found the effects of the ENSO on the UK and Atlantic weather systems can not only occur during the El Niño phase itself but can also occur with a lag of a year. This means that some winters following an El Niño can show noticeable wetter periods of weather and stormy conditions, which is reflective of a more aggressive NAO in nature.

What can we expect for this upcoming winter?

Weather is hard to predict, but based on what we know already there are a few plausible scenarios for the UK this winter 2025:
Autumn/Early Winter (September to December) – Milder than average temperatures can be expected this autumn, with consistent westerly or south-westerly winds bringing wetter weather fronts.

Mid/Late Winter (January to March) – Based on this years record breaking summer temperatures and milder than average start to the autumn season, both reflective of the effects of an El Niño phase; this late winter could see a transition to colder spells.

The overall temperature outlook for 2025 has so far been warmer than average, with the UK experiencing its warmest and sunniest spring earlier in the year. The above average temperatures have persisted over the course of 2025 and are likely set to remain mild for the foreseeable future. Due to the tendency of El Niño phases to increase extremes combined with the warmer than average temperatures, the risk of heavy rainfall is far greater.

Insights from FPSE, What to Plan for?

As a specialist flood risk consultancy firm, we regularly see first hand the damaging consequences of severe flooding on properties and people’s lives. From our experience, this autumn and winter season will likely be no different from any other.

The usual insurance claims extending into the tens of thousands, homeowners living in hotels while their home is under restoration and severe property damage. These consequences are the reality for so many people across the UK, with an estimated 6.3 million properties vulnerable to flooding according to the Environment Agency (EA).

However, the risk of flooding can be reduced by simply being prepared and being proactive by ensuring the following:
Ensure drainage systems are regularly checked and maintained. This is crucial during the autumn months with all the fallen leaves and debris which can block and restrict the flow of drainage infrastructure, ditches and culverts. If you are unsure who’s responsibility it is to maintain a drainage ditch or watercourse at or adjacent to your property, then check out our other blog regarding riparian ownership:

If you have existing flood mitigation measures in place, such as flood barriers, flood doors or flood resistant airbricks, it is paramount that these are maintained accordingly and have their annual servicing. Information on servicing and maintenance should be contained within the products information handover pack.

If you don’t have flood protection measures in place and are concerned about the flood risk to your property, then get in touch with us here at FPSE. We offer a range of bespoke services such as consultation calls (our Flood Map Chat service), comprehensive property surveys and even SuDS/Drainage Designs. These services aim to understand the flood risk at your property and develop mitigation solutions.

Understanding your flood risk is the first step. Acting on it is what protects your property, your project, and your peace of mind. At FPS Environmental, we specialise in helping homeowners, developers, and local authorities build resilience against future storms.To discuss the range of services we offer, please contact us today.

Written by Reece Hewitt – Senior Flood Risk Consultant – MSC BSc (Hons) MCIWEM

19th September 2025