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In May 2026, the United States experienced slightly below-average temperatures overall, with an average anomaly of -0.2°F across 192 cities. Despite this, the western U.S. saw above-average temperatures, and the Northern Rockies and Plains region was the warmest, averaging more than 1.6°F above normal. Long-term data indicates that 185 of the 192 analyzed cities have warmed since 1970, with Reno, Nevada, showing the greatest increase at 7.5°F. Climate attribution analysis shows that San Juan, Puerto Rico, had the highest number of days (28) where temperatures were at least two times more likely due to climate change (CSI level 2 or higher).

The May 2026 report highlights that the month was the second-warmest on record globally, with carbon dioxide levels reaching a new monthly peak of 432.3 ppm. In the United States, spring 2026 was the second-warmest on record for the contiguous U.S., while 77% of the region experienced abnormally dry or drought conditions as of early June. The report also notes a developing potentially very strong El Niño and record-low snowpack in several western states.

Analysis of 144 U.S. cities shows that 90% have experienced increased hourly rainfall intensity since 1970, with the highest average increases in the Upper Midwest. Projections indicate that at 2°C of global warming, 85% of U.S. counties will likely see a 10% or higher increase in precipitation on the heaviest 1% of days, with disproportionate risks for Black communities and rural areas.

A severe marine heat wave is impacting the northeast Pacific Ocean, with temperatures 2-5°F above normal and peak anomalies reaching 11°F. The event is strongly influenced by human-caused warming, which has increased the heat wave's footprint and duration.

In March 2026, the United States experienced unprecedented warmth with an average temperature anomaly of 5.8°F across 192 cities. The Southwest was the warmest region, with temperatures more than 10.4°F above normal, and Phoenix recorded the highest individual city anomaly at 12.5°F. Long-term trends show that 188 of the 192 analyzed cities have warmed since 1970, with Wheeling, West Virginia, seeing the greatest increase of 11.7°F. Climate attribution analysis using the Climate Shift Index (CSI) indicates that in Flagstaff, Arizona, temperatures on 28 days in March were made at least two times more likely due to climate change.

As of March 30, 2026, the western U.S. is experiencing a historic snow drought, with snow water equivalent at its lowest record for April 1 and 65% below the 1991-2020 normal. This condition is attributed to a record-warm winter and a record-shattering March heat wave fueled by heat-trapping pollution. Long-term trends from 1955 to 2023 show an 18% average decline in April 1 snowpack across 652 monitoring stations, with snow droughts growing 28% longer between 1980 and 2018. These trends increase risks for water supplies, hydropower, and wildfires, with projections suggesting a further 25% decline in snow water equivalent by 2050.

April 2026 was the fourth-warmest month globally on record, with the contiguous U.S. experiencing its third-warmest April. The report highlights severe drought in the Southeast U.S., record-low Western snowpack, and a persistent marine heat wave off the coasts of California and Mexico. Using the Climate Shift Index (CSI), the analysis attributes springtime warming trends in 98% of analyzed U.S. cities to human-caused climate change, with exceptional warmth noted in Honolulu and San Juan. Forecasts indicate a high probability of a strong El Niño developing later in 2026, potentially driving global temperature anomalies above 1.8°C relative to pre-industrial levels by early 2027.

In 2025, the U.S. generated a record 853,210 GWh from solar and wind, accounting for 19% of total electricity generation. This represents a more than threefold increase since 2016, with solar generation growing more than seven-fold and wind doubling. Despite this growth, the document notes that the U.S. faces new challenges, including the repeal of clean energy tax credits via the One Big Beautiful Bill Act of 2025 and the U.S. withdrawal from the Paris Agreement in 2026. These policy shifts, combined with rising electricity demand from data centers, are projected to increase heat-trapping pollution and raise average annual household energy costs by over $280 by 2035.

Between December 2025 and February 2026, human-caused climate change significantly influenced global temperatures, with more than one in six people daily experiencing temperatures at least twice as likely due to climate change. In the United States, a sharp divide occurred: western states saw record-breaking warmth, with nine states experiencing their warmest December-February on record and Casper, Wyoming, recording the highest temperature anomaly globally among 960 analyzed cities. Conversely, the eastern U.S. faced below-average temperatures and cold snaps that the Climate Shift Index (CSI) indicates were made less likely by climate change. The record warmth in the west has led to low snowpack in Oregon, Colorado, and Utah, threatening water supplies and increasing wildfire risks.

Between December 2025 and February 2026, climate change significantly boosted global temperatures, with over one in six people experiencing strong climate influence daily. Nearly 228 million people faced 30 or more risky heat days added by climate change, with 81% of these individuals residing in Africa. The analysis highlights that in 45 countries, all risky heat days during this period were driven by climate change, and 124 countries saw the average person experience at least 30 days of strong climate influence (CSI level 2 or higher).

Analysis of USA National Phenology Network data shows that first spring leaves now emerge earlier in 88% of 242 major U.S. cities, shifting by an average of six days since 1981. This trend, combined with a freeze-free growing season that has stretched 21 days longer on average across 173 cities between 1970 and 2025, extends allergy seasons and increases the risk of 'false spring' crop losses. Ecological disruptions include potential mismatches between bird migration and the peak abundance of food sources.

In February 2026, the United States experienced an average temperature anomaly of 2.1°F across 192 cities. While the Northeast was the coldest region with an average anomaly of -3.4°F, the Northern Rockies and Plains were the warmest, exceeding normal temperatures by more than 8.4°F. Long-term data indicates that 173 of the 192 analyzed cities have warmed since 1970, with Albany, Georgia, showing the greatest increase at 8.4°F. Climate attribution analysis using the Climate Shift Index (CSI) found that San Juan, Puerto Rico, had 16 days where temperatures were at least five times more likely due to climate change.

March 2026 was the warmest March on record for the contiguous U.S., characterized by a historic snow drought in the West and extreme heat that increased cooling energy demand. Globally, the month was the second-warmest on record, with Arctic sea-ice reaching a near-record low maximum. In the U.S., severe drought affected 77% of the contiguous region, while Hawaii experienced record-breaking precipitation due to Kona lows.

Analysis by Climate Central indicates that all 25 analyzed coffee-producing countries, representing 97% of global production, experienced an increase in 'coffee-harming heat' (temperatures above 30°C) between 2021 and 2025 due to carbon pollution. The top five producers—Brazil, Vietnam, Colombia, Ethiopia, and Indonesia—saw an average of 57 additional days of such heat annually. Brazil, the largest producer, experienced 70 extra days of coffee-harming heat per year on average. These conditions threaten both arabica and robusta coffee varieties, with arabica being more sensitive to heat. The report warns that land suitable for coffee farming could decrease by 50% by 2050 without adaptation, potentially leading to deforestation as farmers move to higher elevations.

The document details how climate change disrupts U.S. transportation systems through acute events like hurricanes and chronic stressors like sea level rise. It highlights significant projected costs for asphalt maintenance and railroad delays, the vulnerability of coastal highways and bridges, and the necessity of proactive adaptation, such as using heat-resistant materials and nature-based solutions, to mitigate economic losses.

In January 2026, the United States experienced an average temperature anomaly of -1.2°F, with 133 cities recording cooler-than-average conditions. Despite this national trend, the western U.S., particularly the Northern Rockies & Plains, saw significant warming, with Helena, Montana, recording the highest anomaly at 9.1°F. Long-term data indicates that 191 of the 194 analyzed cities have experienced warming trends since 1970, with Great Falls, Montana, showing the largest increase of 9.6°F. Climate attribution analysis using the Climate Shift Index (CSI) highlighted that San Juan, Puerto Rico, had 24 days where temperatures were at least five times more likely due to climate change.

February 2026 was the fifth-warmest month globally on record, with the contiguous U.S. experiencing its second-warmest winter in 132 years. A critical 'snow drought' affected the western U.S., where snow-covered areas in January were only 34% of normal, threatening water supplies for agriculture and energy. Climate Central's analysis indicates that human-driven climate change significantly influenced winter temperatures, particularly in the Southwest, and is the primary cause of spring warming in 98% of 241 examined U.S. cities.

Analysis of 244 U.S. weather stations shows that 86% of locations have seen an increase in extremely warm winter days since 1970, with the coldest day of the year warming by an average of 7°F across 242 locations.

The document details the impact of rising temperatures on winter sports, noting that all cities hosting the Winter Olympics since 1950 have warmed. It highlights that the 2026 host cities, Milan and Cortina d'Ampezzo, have seen significant temperature increases and a decrease in freezing days. Projections indicate a sharp decline in climate-reliable host sites by the 2050s, particularly for the Paralympic Games held in March.

2025 was Earth's third-warmest year on record, with average temperatures 1.3°C above pre-industrial levels. This continues a heat streak driven by fossil fuel pollution, pushing the planet toward the 1.5°C long-term warming limit, which could be exceeded by 2030. While global electricity demand is increasingly met by renewables, the U.S. has recently rolled back clean energy policies and withdrawn from key international climate agreements.