ClimaMeter

Understanding Extreme Weather in a Changing Climate


ClimaMeter is an experimental rapid framework for understanding extreme weather events in a changing climate based on looking at similar past weather situations. Find out more here and follow us on X

🆕 Starting from December 6, 2024, our analyses integrate ERA5 data, providing coverage from 1950 with a latency of approximately 5 days and GFS forecasts, for the most recent days where ERA5 data is not yet available. This upgrade ensures more robust data retrieval; extends our historical period up to 1950, improving the research of analogues; makes it possible to perform analysis on the same day an event occurs. For more details, click here.

February 2025 floods in Queensland mostly exacerbated by human-driven climate change

In early February 2025, Queensland experienced severe flooding, particularly impacting the northeastern regions. The Australian Bureau of Meteorology reported that some areas received over 1,000 millimetres of rainfall, with Paluma recording more than 175mm within a three-hour period.  The Shire of Hinchinbrook, including towns like Ingham, was among the hardest-hit areas. The Herbert River reached record levels, inundating homes and businesses. In Ingham, approximately 6,700 properties lost power after the local substation was deactivated for safety reasons.  Townsville also faced significant challenges. The Ross River Dam reached 163.8% capacity, leading to the closure of the area to the public and halting traffic. Mandatory evacuations were ordered for six suburbs designated as "black zones," including Cluden, Oonoonba, Hermit Park, Railway Estate, Idalia, and Rosslea. The flooding resulted in at least one fatality and prompted mass evacuation orders in coastal regions. Emergency services conducted numerous rescues, including evacuations and assistance to individuals stranded on rooftops.

Climameter found that meteorological conditions similar to those producing Queensland Floods are up to 17 mm/day (up to 20%) wetter over the coast of Queensland. Additionally, conditions are up to 5 km/h (up to 20%) windier offshore Queensland and up to 1.5 ºC warmer in the present compared to the past. We interpret Queensland floods as an event driven by exceptional meteorological conditions whose characteristics can be ascribed to human driven climate change.

Image: Scott Radford-Chisholm/AAP Image/Reuters

Heavy precipitation and strong winds in storm Éowyn mostly strengthened by human-driven climate change

Storm Éowyn, an exceptionally powerful extratropical cyclone, struck Ireland, the Isle of Man, and the United Kingdom on January 24, 2025. Named by the UK Met Office on January 21, 2025, it was the fifth storm of the 2024–25 European windstorm season. Éowyn displayed unprecedented wind speeds, with sustained wind above 80 mph (135 km/h) and gusts reaching up to 135 mph (217 km/h) in Cairnwell, Scotland, making it comparable to a category 1 hurricane, leading to widespread red weather warnings across the affected regions. The impact of Storm Éowyn was devastating. Over 1 million people in Ireland, Northern Ireland, and Scotland were left without electricity and sustained significant property damage, including the collapse of a 100-year-old building in Hale, Manchester, and the fall of a 166-year-old Himalayan cedar at the Royal Botanic Garden Edinburgh. 

Climameter found that windstorms similar to Storm Éowyn are more intense with up to 4 hP deeper, up to 8 km/h  (10%) windier over the Atlantic coasts of Ireland and France, and up to 6 mm/day (up to 15%) wetter in the present than they would have been in the past. We interpret Storm Éowyn as an event driven by rare meteorological conditions whose characteristics can be mostly ascribed to human-driven climate change.

Image: source BBC news  

January 2025 California wildfires have been fueled by meteorological conditions strengthened by human-driven climate change

Beginning on January 7, 2025, multiple catastrophic wildfires, which are still ongoing, have impacted the Los Angeles metropolitan area and its surrounding regions. The fires were fueled by the interplay of different meteorological and hydrological conditions: very low humidity, dry conditions (with very little moisture over the past several months), and Santa Ana winds, exceeding 130-160 km/h in some places. The Santa Ana winds typically originate from cool and dry high-pressure masses in the Great Basin. The dry and powerful winds blow down the mountains towards the Pacific Coast, with gusts that can reach hurricane strength. As of January 10, the wildfires have resulted in ten casualties, damaged thousands of structures, forced nearly 180,000 residents to evacuate, and burnt around 30,000 acres.

Climameter found that meteorological conditions similar to those triggering January 2025 California wildfires are up  5°C warmer, 3 mm/day (up to 15%) drier and up to 5 km/h (up to 20%) windier in the present compared to the past, in the area interested by the fires.  We interpret  January 2025 California wildfires as an event driven by very rare meteorological conditions whose characteristics can be ascribed to human-driven climate change.

A Firefighter fights the flames from the Palisades Fire burning the Theatre Palisades on January 8th, 2025 in the Pacific Palisades neighborhood of Los Angeles. Image: source Apu Gomes/Getty Images 

Low confidence prevents ascribing cyclone Chido intensity to human-driven climate change

Cyclone Chido, an intense tropical cyclone in the 2024-2025 South-West Indian Ocean season, caused catastrophic damage in Mayotte and severe disruptions in the Comoros, with winds exceeding 200 km/h destroying precarious housing and leaving the island in devastation. Preliminary reports indicated at least 14 deaths and 250 injuries, but officials warned the toll could be significantly higher, particularly in shantytowns where undocumented residents lived. Rescue operations were hindered by challenging communication, cultural burial practices, and limited administrative processes, as French authorities launched an emergency response to address the crisis.

ClimaMeter concludes that low-pressure systems making landfall in Comoros and Mayotte, such as Cyclone Chido, generally display precipitation and wind patterns similar to past events. However, with the influence of anthropogenic climate change, the warmer environment (+1.5°C) in which these systems develop can enhance both their intensity and rainfall potential. Given the exceptionality of the cyclone and the lack of similar events in our dataset, we cannot disentangle the influence of natural variability in driving the cyclone trajectory.

Image: source l'Humanité

Heavy precipitation and strong winds in storm Darragh locally strengthened by human-driven climate change

Storm Darragh, the fourth named storm of the 2024-2025 season, struck Ireland and the UK on December 6-7, 2024, bringing hurricane-force winds exceeding 160 km/h and heavy rainfall. The storm caused widespread power outages, affecting nearly 400,000 homes in Ireland and 130,000 households in the UK, along with significant transportation disruptions. The Met Office issued rare red weather warnings, highlighting the storm's potential for structural damage and danger to life.

ClimaMeter found that that windstorms similar to Storm Darragh are more intense with up to 2 hP deeper, up to 4 km/h  (5%) windier over the Atlantic coasts of Ireland and France, and  up to 5mm/day ( up to 10%) wetter  in the present than they would have been in the past. We interpret Storm Darragh as an event driven by very exceptional meteorological conditions whose characteristics can be ascribed to human driven climate change.

Waves crash against the harbour wall at Porthcawl in south Wales during Storm Darragh. Photograph: Matthew Horwood/Getty Images

Heavy Precipitations in South-Eastern Spain DANA mostly strengthened by human-driven climate change

Extreme thunderstorms associated with high-level depression (DANA, in Spanish) hit the eastern Spanish coast, leading to unprecedented rainfall, with up to 630 mm recorded in Toris, Valencia, over 24 hours. The Valencian Community bore the brunt of these catastrophic events, facing severe floods, hailstorms, and tornadoes that resulted in over 200 deaths, dozens of missing persons, and widespread devastation, especially in Valencia, Castellón, Málaga, and Albacete

We conclude that depressions similar to the DANA that cause floods in southeastern Spain are up to 7 mm/day (an increase of up to 15%) wetter over the Mediterranean coast of Spain in the present than they would have been in the past.  Additionally, conditions are up to 3°C warmer in the present compared to the past, which favors the formation of thunderstorms over the Mediterranean basin during DANA events. We interpret this DANA as an event driven by very exceptional meteorological conditions, whose characteristics can mostly be ascribed to human driven climate change. We remark that, for this event, we have low confidence in the robustness of our approach given the available climate data, as the event is  very exceptional in the data record. To ensure robustness of our findings, we have increased the statistics of analogues to include 20 similar events in past and present periods.

Image: AP photo Manu Fernandez

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