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Climate change accounted for 27% of the rate of heat-related emergency room visits in the U.S. during 2018-2025. August 2026 was the warmest August on record globally, with record warmth affecting 13.2% of global land and ocean areas. In the U.S., Summer 2026 was the warmest on record for the contiguous region, and August 2026 was the warmest August for average, maximum, and minimum temperatures since 1895. Drought affected at least 81% of the contiguous U.S. as of September 8, 2026, and nearly 8.3 million acres burned year-to-date, driven by increased 'fire weather' days. Attribution analysis using the Climate Shift Index (CSI) indicates human-caused climate change drove summertime warming trends in 91% of analyzed U.S. cities. Additionally, a strong El Niño event is projected to peak around February 2027, with global temperature anomalies potentially reaching 1.7C above pre-industrial levels.

In June 2026, the United States experienced slightly above-average temperatures, with an average anomaly of 0.7°F across 192 analyzed cities. The Southwest was the warmest region, with temperatures more than 2.9°F above normal, and Flagstaff, Arizona, recorded the most unusual warmth at 4.0°F above normal. Long-term trends show that 189 of the 192 cities have warmed since 1970, with Reno, Nevada, seeing the greatest increase of 10.6°F. Climate attribution analysis using the Climate Shift Index (CSI) indicates that San Juan, Puerto Rico, had 30 days where temperatures were at least two times more likely due to climate change.

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.

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 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.

The document warns of a rare two-day 'Moderate Risk' of severe weather in the Midwest and Deep South on March 14-15, 2025, driven by temperatures 15-25°F above mid-March averages. It links this early-season warmth to human-caused climate change and notes a long-term increase in Convective Available Potential Energy (CAPE) and the frequency of extreme tornado outbreaks in the U.S.

Hurricane Beryl, the earliest Category 5 hurricane on record, was fueled by ocean temperatures 2°–3°F warmer than normal, conditions made 100–400 times more likely by human-caused climate change.

The document outlines how human-induced climate change has increased the probability of intense heat waves, severe droughts, and large forest fires in the U.S., citing data from NOAA and other scientific bodies to show that these events are becoming more frequent and severe than natural variability alone can explain.