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In 2025, the U.S. experienced 23 billion-dollar weather and climate disasters costing $115 billion, ranking it the third-highest year on record. The year was dominated by a record 21 billion-dollar severe storm events and the costliest wildfire in U.S. history, the Los Angeles wildfires. Since 1980, the frequency of such disasters has surged, with the average time between events dropping from 82 days in the 1980s to just 10 days in 2025.

The report finds that while December 2025 temperatures in the U.S. were evenly split between warmer-than-average and cooler-than-average cities, long-term trends show nearly all analyzed cities have warmed since 1970. The Southwest was the most unusually hot region, with Casper, Wyoming, recording the highest anomaly. Climate signal (CSI) was minimal nationwide, though San Juan, Puerto Rico, saw 10 days where temperatures were at least five times more likely due to climate change.

January 2026 was the fifth-warmest January on record globally, characterized by significant temperature anomalies in the U.S. West and record-low snowpacks in several states. The document highlights the transition of NOAA to the Relative Oceanic Niño Index (RONI) to better account for climate change in ENSO tracking. Attribution analysis using the Climate Shift Index (CSI) indicates that extreme warmth in the northern U.S. and specific cities like San Juan and Honolulu was strongly driven by carbon pollution.

The document argues that talking about climate change is a critical individual action to normalize the topic and overcome the common misperception that others do not care about the issue. It provides a set of communication guidelines based on science and expert advice, emphasizing the use of shared values, personal stories, and empathetic listening over technical jargon or argumentative approaches. The guide highlights a gap in U.S. public perception, noting that while 63% of Americans are concerned about climate change, they believe only 43% share that concern, which often leads to silence and inaction.

The document reports that 2025 is virtually certain to be among the top five hottest years globally, driven by rising carbon pollution from fossil fuels. In the U.S., record high temperatures significantly outpaced record lows, and the year saw a record-costly start for billion-dollar weather and climate disasters, including the most expensive wildfire event on record in Los Angeles. Globally, carbon pollution intensified Hurricane Melissa, which devastated Jamaica. The report also highlights a trend of 'hydroclimate whiplash' contributing to both the Los Angeles fires and deadly flash floods in Texas, while noting that the U.S. has rolled back key clean energy policies and is set to withdraw from the Paris Agreement by January 2026.

The document introduces attribution science as a method to measure how human-caused climate change affects the likelihood, frequency, and intensity of weather events by comparing current observations with simulated 'counterfactual' worlds. It details Climate Central's specific tools, such as the Climate Shift Index (CSI) for air and sea surface temperatures and the Tropical Cyclone CSI for hurricane wind speeds. The guide distinguishes between different types of attribution—event, trend, source, and impact—and notes that while temperature-related events are highly quantifiable, other severe weather like tornadoes remains an active area of research.

In November 2025, the United States experienced an average temperature anomaly of 2.1°F across 194 analyzed cities, with the western half of the country seeing exclusively above-average temperatures. The Southwest, South, and Northern Rockies and Plains were the most unusually hot regions, with anomalies exceeding 4.8°F. Waco, Texas, recorded the highest anomaly at 7.5°F. Long-term trends show 183 of 194 stations have warmed since 1970, with El Paso, Texas, seeing the greatest increase of 6.9°F. Climate attribution via the Climate Shift Index (CSI) highlighted San Juan, Puerto Rico, with 27 days at CSI 5, meaning temperatures were at least five times more likely due to climate change.

In 2025, the contiguous U.S. experienced its fourth-warmest year on record and 23 billion-dollar weather and climate disasters, totaling $115 billion in damages. Globally, 2025 was the third-warmest year since 1850, with NOAA data indicating it was approximately 1.3°C warmer than the pre-industrial average. The year was marked by record-breaking December heat in the U.S. Southwest and devastating atmospheric river flooding in Washington and Oregon.

The document reports that November 2025 was the third warmest on record globally and the fourth warmest for the contiguous U.S. It highlights a long-term trend of warming winters in the U.S., where the coldest day of the year has warmed by approximately 7°F since 1970. The briefing also notes significant regional anomalies, such as extreme warmth in Texas and heavy rainfall in southern California, while discussing the ongoing La Niña advisory and its expected impacts on weather patterns through early 2026.

The document outlines how human-caused climate change affects different weather phenomena. It states that extreme heat, marine heat waves, and the intensity of heavy rain and hurricanes are increasing, while extreme cold is becoming less likely. It notes that while climate change increases hot, dry conditions contributing to droughts and wildfires, other factors like land use also play a role. For localized severe storms, the document explains that current climate models cannot yet accurately simulate specific events to make direct attribution statements.

Analysis of 245 U.S. cities shows that 92% experienced rising November temperatures since 1970, with an average increase of 2.4°F. The highest warming occurred in El Paso, Texas (6.4°F), followed by Phoenix and Tucson, Arizona. This warming trend, alongside earlier springs and hotter summers, threatens cranberry production in the Northeast through frost vulnerability and 'cranberry scald', potentially increasing food prices.

The report identifies 5,500 hazardous facilities along US coastlines at risk of 100-year coastal flooding by 2100 under a high-emissions scenario (RCP 8.5). It highlights that marginalized populations—including renters, non-voters, and those in poverty—are 15-41% more likely to live within 1 kilometer of these sites. The risk is heavily concentrated, with nearly 80% of at-risk facilities located in seven states, and specific infrastructure like fossil fuel ports and terminals are particularly vulnerable, with over 40% expected to be at risk.

Analysis of 244 U.S. cities shows that winters are the fastest-warming season for most of the country, with average temperatures increasing by 3.9°F since 1970. This trend is characterized by fewer freezing nights, shorter cold streaks, and a significant increase in warmer-than-normal winter days, particularly in the Northeast and Upper Midwest. These changes threaten mountain snowpack, crop yields for the $27 billion fruit and nut industry, and the winter recreation economy, while potentially increasing pest-related health risks and allergy durations.

In October 2025, the United States experienced an average temperature anomaly of 2.0°F across 192 analyzed cities, with the Ohio Valley seeing the most unusual heat at 4.89°F above normal. Fairbanks, AK, recorded the highest individual city anomaly at 7.1°F. Long-term data indicates that 190 of 191 analyzed stations have shown positive warming trends since 1970, with Wheeling, WV, experiencing the fastest increase at 7.8°F. Climate change influence was particularly strong in San Juan, PR, which had 29 days at a Climate Shift Index (CSI) of 5, and Honolulu, HI, where both cities saw at least two weeks of CSI values of 2 or higher.

Climate Central analysis of 221 marathons indicates that the probability of optimal, cool race-day temperatures is decreasing due to global warming. For recreational runners in the U.S., the current average chance of optimal temperatures is 27%, and this is projected to decline in 46 of 51 analyzed U.S. marathons by 2045 if high levels of heat-trapping pollution continue. The analysis highlights regional disparities, with the Northwest having the best current odds (55%) and the Southwest the worst (14%). Beyond performance, the document notes that rising heat and humidity increase risks of heat-related illness and that climate-driven air quality issues, such as wildfire smoke, further threaten runner health.

The report finds that 86% of analyzed global marathons will see a decline in the odds of optimal running conditions by 2045. While elite women are more resilient to heat, elite men are most affected, particularly at the Tokyo Marathon, which is projected to see the largest decline in ideal conditions among the Abbott World Marathon Majors. The analysis highlights that the 2025 Tokyo and Berlin Marathons experienced unusual heat made two to three times more likely by climate change. Shifting race start times to sunrise is identified as a potential adaptation to increase the likelihood of optimal temperatures for most runners.

The analysis shows that 161 of 192 analyzed U.S. cities experienced hotter-than-average temperatures in September 2025, with an average anomaly of 1.5°F. The Northwest region saw the most unusual heat, averaging 3.42°F above normal, while Spokane, WA, recorded the highest individual city anomaly at 7.8°F. Long-term trends indicate widespread warming since 1970, with Reno, NV, showing the fastest increase at 10.8°F. Climate Shift Index (CSI) data highlighted strong climate change influence in several cities, most notably San Juan, PR, which had 22 days at CSI 5.

Climate Central analysis of 204 U.S. cities shows that the first fall freeze is arriving later in 88% of locations, delaying the date by an average of 12 days since the early 1970s. This trend extends the growing season for ragweed, prolonging allergy seasons, and disrupts ecological cues for bird migration, hibernation, and fall foliage. Additionally, the delay affects the $27 billion U.S. fruit and nut industry by reducing necessary chilling periods and allowing disease-carrying insects like mosquitoes to persist longer into the year.

The document explains that rising global temperatures increase 'atmospheric thirst,' where the atmosphere absorbs more moisture from the land. In the western U.S., this heat-driven demand has replaced lack of precipitation as the leading cause of exceptional drought since 2000, contributing to a multi-decade megadrought in the Southwest and increasing wildfire risk in California and Nevada.

The October 2025 briefing reports that global temperatures remained exceptionally high, with the month ranking as the third warmest on record. In the U.S., warming fall temperatures have delayed the first freeze in 88% of analyzed cities, while significant drought persists across 67% of the contiguous U.S. despite localized heavy rainfall in Southern California.