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In October 2024, 185 of 191 analyzed U.S. cities were warmer than normal, with the Southwest experiencing particularly high anomalies. The report highlights that 19 cities saw their hottest October on record and identifies specific states, including Texas, Arizona, and New Mexico, where climate change significantly increased the likelihood of extreme temperatures as measured by the Climate Shift Index.

A rapid analysis by World Weather Attribution indicates that heavy 1-day rainfall events in central and southeastern Spain are approximately 12% more intense and twice as likely in the current climate, which is 1.3°C warmer than preindustrial levels. The analysis focuses on the extreme precipitation event of October 29, 2024, which caused devastating floods in regions like Valencia and Catalonia, resulting in over 200 deaths. While the study used daily rainfall data over a large region—potentially underestimating the intensity of localized sub-daily extremes—the findings align with the Clausius-Clapeyron relationship and existing evidence of climate change signals in European rainfall extremes.

In November 2024, 166 out of 191 analyzed U.S. cities were warmer than normal, with the South averaging 5.7°F above average. While long-term warming trends are evident—with El Paso, Texas warming 6.4°F since 1970—daily climate attribution signals (CSI 3 or higher) remained rare due to fall weather variability, though they were most prominent in Gulf Coast states and Puerto Rico.

The October 29, 2024, floods in Valencia, Spain, were driven by a low-pressure system (DANA) that utilized an atmospheric river carrying moisture from an unusually warm Tropical Atlantic. Analysis using the Climate Shift Index: Ocean and OISST data indicates that human-caused climate change made these elevated sea surface temperatures 50 to 300 times more likely.

The report finds that human-induced climate change increased the intensity and likelihood of heavy rainfall associated with Hurricane Milton in central Florida. Using the IRIS model, the analysis indicates that climate change increased the frequency of storms with Milton's wind speeds by approximately 40%, meaning the storm would have likely made landfall as a Category 2 rather than a Category 3 hurricane without global warming. Additionally, sea surface temperatures along Milton's track were 1°C warmer than in a world without climate change, making such temperatures 400 to 800 times more likely. The report also assesses Florida's adaptation measures, noting that while building codes are among the toughest in the US, the state's planning remains largely reactive and fails to adequately address social vulnerabilities in low-income and minority communities.

Between October 1 and 6, 2024, over 120 million people in Japan experienced unusual heat that was made at least 3 times more likely by human-caused climate change. At least 74 cities recorded temperatures of 30°C or higher, with conditions 5°C to 8°C above the 1991-2020 average. The analysis uses the Climate Shift Index (CSI), noting that 259 cities reached CSI level 3, while some cities like Kusatsu, Toyota, and Miyazaki reached CSI level 5, indicating an exceptional climate change event. The document also notes broader impacts of extreme heat in Japan, including a record 252 deaths in Tokyo from a summer heat wave, reduced agricultural output for vegetables, dairy, and fish, and delayed peak fall foliage in northern and eastern regions.

In October 2024, 185 of 191 analyzed U.S. cities were warmer than normal, with 19 cities recording their hottest October on record. The Southwest experienced particularly high anomalies, and cities in California, Arizona, New Mexico, Texas, and Florida saw the highest frequency of days where temperatures were made at least three times more likely due to climate change.

An attribution study on the September 2024 Central European floods finds that human-induced climate change roughly doubled the likelihood of such an event and increased its intensity by 7%. While improved forecasting and emergency management reduced fatalities compared to the 1997 and 2002 floods, the scale of the event overwhelmed infrastructure in several urban centres, causing damages estimated at several billion Euros.

Analysis by Climate Central indicates that June-August 2024 was the hottest season on record, with carbon pollution significantly increasing the frequency and intensity of risky heat days globally and in the U.S. Approximately 2 billion people worldwide experienced 30 or more risky heat days made at least three times more likely by climate change. In the U.S., the average person experienced 20 additional risky heat days, with the highest impacts concentrated in the South, Southeast, and Southwest, particularly in Florida and Puerto Rico.

The report finds that June through August 2024 was Earth's hottest season on record, with human-induced climate change significantly increasing the frequency and intensity of extreme heat worldwide. Using the Climate Shift Index (CSI), the analysis shows that one in four people experienced temperatures made at least three times more likely by climate change every day of the season. Global exposure peaked on August 13, 2024, affecting 4.1 billion people. The average person experienced 17 additional 'risky heat days' (temperatures above the 90th percentile) due to climate change. Over 2 billion people experienced 30 or more such days, with extreme concentrations in the Caribbean, Western Asia, Micronesia, Northern Africa, and Southern Europe. Additionally, 72 countries experienced their hottest June-August period since 1970, and 180 Northern Hemisphere cities faced dangerous extreme heat waves that were, on average, 21 times more likely due to human-caused warming.

The briefing links the increased frequency and intensity of US extreme weather events, such as the July 2023 heatwave and August 2024 California wildfires, to climate change driven by fossil fuels. It highlights that US oil and gas production emissions rose roughly 42% between 2011 and 2022 and notes that 88 large fossil fuel and cement companies are responsible for 48% of the rise in fire-danger conditions in the region. The document argues for corporate accountability, citing a Climate Analytics estimate that the 12 most polluting companies are responsible for USD 15 trillion in economic damages from 1985 to 2018. While the US has seen significant growth in solar and wind capacity and electric vehicle sales, primary energy consumption remains dominated by petroleum (38%), natural gas (36%), and coal (9%) as of 2023.

The document details how rising sea surface temperatures, driven by human-caused climate change, are increasing the frequency and intensity of rapid intensification in tropical cyclones. It highlights that 70% of billion-dollar tropical cyclones in the U.S. since 1980 underwent rapid intensification, contributing to over $1.4 trillion in damages and nearly 7,000 deaths.

The report finds that August 2024 temperatures were elevated across much of the U.S., particularly in the South and Southwest, with Texas experiencing the highest anomalies. Using the Climate Shift Index (CSI), the analysis shows that the Southwest and South had the highest number of days where temperatures were at least three times more likely due to climate change. San Juan, Puerto Rico, recorded its hottest August on record, and Amarillo, Texas, was the most unusually hot city, 6.27°F above normal.

The report finds that September 2024 was unusually warm across much of the U.S., with 171 of 191 analyzed cities experiencing warmer-than-normal temperatures. While the highest temperature anomalies occurred in the Midwest and northern Great Plains, the strongest climate change signals (CSI values) were concentrated in the Southwest and Florida.

The report examines the intersection of climate change and democratic processes, detailing how extreme heat, floods, and wildfires disrupt voter registration, polling access, and ballot counting. It provides evidence of recent climate-driven disruptions in the US, India, and Pakistan, and analyzes temperature anomalies in 60 countries during the 2024 election cycle. The authors advocate for systemic changes, such as flexible voting arrangements, improved risk mapping, and updated emergency statutes, to protect the fundamental right to vote on a warming planet.

A late summer heat event in the eastern United States, affecting approximately 120 million people, has been made significantly more likely by human-caused climate change. The event is characterized by record-breaking temperatures, high humidity, and heat indices reaching 115°F, posing severe health risks to vulnerable populations, particularly children.

The analysis finds that human-caused climate change has significantly increased the frequency of dangerous nighttime temperatures globally, affecting billions of people. Using the Climate Shift Index, the report quantifies additional nights above 18°C, 20°C, and 25°C, noting that these temperatures disrupt sleep and increase risks of cardiovascular conditions and mortality. The most severe impacts are observed in tropical regions and urban areas due to heat island effects, with specific cities in India, Indonesia, and Africa experiencing an additional month or more of extreme nighttime heat.

This analysis quantifies the global increase in dangerously hot summer nights attributed to human-caused climate change. Using the Climate Shift Index, the report finds that billions of people are experiencing additional weeks per year of nighttime temperatures exceeding critical thresholds (18°C, 20°C, and 25°C), which impairs human health by preventing recovery from daytime heat and disrupting sleep.

The report finds that July 2024 temperatures were elevated in the eastern and western thirds of the United States, with the West Coast showing particularly high anomalies. Using the Climate Shift Index (CSI), the analysis identifies the Southwest as having the strongest climate signal, with cities averaging at least 14 days where temperatures were at least three times more likely due to climate change. Specific cities like Spokane, Washington, and Reno, Nevada, showed significant temperature anomalies and long-term warming trends since 1970.

The report finds that June 2024 was historically hot across the United States, with climate change making temperatures 2.3 times more likely on average. The Southwest experienced the most extreme anomalies, with Nevada's temperatures being 8.2 times more likely due to climate change and the region seeing an average of 4.2 additional days above 90°F. Analysis of 191 ACIS stations showed that 12 experienced their hottest Junes on record, and 168 stations had at least one day where temperatures were at least twice as likely due to climate change.