US March weather extremes show climate change fingerprint
Mar 23rd 2026 · United States
March delivered a patchwork of extremes across the United States, including an unusually strong western heatwave, rare southern snow and heavy rains, and scientists say the heat signal bears a clear climate change fingerprint.
- A severe March heatwave in California, Nevada and Arizona produced record or near record temperatures and widespread heat warnings.
- Scientists' rapid analysis found human caused warming made this kind of western heatwave about four times more likely over the last decade.
- Jet stream ridges and troughs drove simultaneous extremes, producing heat in the west and cold or snowy conditions in the east and south.
- Heavy rainfall and flooding affected Hawaii while a storm system from the midwest to the east coast caused widespread outages and heavy snow in several states.
- A warmer atmosphere can hold more moisture and increase the risk of heavier precipitation, and heat records are outpacing cold records as the planet warms.
- Experts urge stronger preparedness and response as extremes grow, noting recent cuts to FEMA funding have reduced emergency capacity.
Articles
- Weather extremes gripping US bear climate crisis ‘fingerprint’, experts say www.theguardian.com
- Heat Wave in California and Other Western States Wilts a More Air-Conditioned U.S. www.nytimes.com
- Record-shattering March temperatures in Western North America virtually impossible without climate change www.worldweatherattribution.org
- UN weather agency warns of record ‘climate imbalance’ as planetary warming accelerates news.un.org