Former government officials and scientists are warning that deep cuts to the main US climate agency have badly weakened the country's ability to forecast, study and respond to extreme weather. The warnings come as the nation faces a string of hazards linked to a potentially historic El Niño this winter.

Since the start of his second term, President Donald Trump has targeted the National Oceanic and Atmospheric Administration (Noaa) by reducing staff, canceling contracts and grants, and closing databases and research laboratories. The agency, long seen as a global leader in climate science and forecasting, has lost roughly 20% of its workforce since January 2025. The National Weather Service, which sits inside Noaa, has also been affected, with hundreds of meteorological and technical jobs still unfilled across its 122 forecast offices.

This year's super El Niño is marked by warmer than average sea surface temperatures along the equator, and it can drive extreme weather around the world. It is already well above typical levels and is expected to strengthen through the northern hemisphere's autumn and winter. It is forecast to intensify storms in parts of the American west, lift sea levels in California by up to a foot, and raise the risk of debris flows, landslides and flash floods.

"The system has not really been tested since all the cuts happened," said Tom Di Liberto, a former Noaa climate scientist who is now media director of Climate Central. "Whether we as a country can handle the kind of coast-to-coast extremes that could potentially happen this winter is a big question," he added.

Workforce data from the US Office of Personnel Management, last updated in August, shows Noaa has lost more than 3,000 employees since January 2025, the largest drop in a decade. The public affairs team was roughly halved, and information technology management staff fell by about 27%. More than 500 science positions were lost against only 46 new hires. Meteorologists and meteorology technicians were down about 10% heading into autumn. Overall, the agency has hired just 525 people in that period, leaving a deficit of about 2,500.

The strain is already visible. Weather balloon launches have been delayed or limited, leaving parts of the Great Plains less prepared for tornadoes. Warnings to rural Alaska communities were restricted, in a state where more than 1,500 people were displaced by floods earlier this year. The Government Accountability Office found that the weather service failed to provide adequate multilingual alerts because of staffing and funding cuts, putting 26 million people in the US at higher risk.

Funding for research has also shrunk. Grant Witness, which tracks federal science grants, said dozens of terminated grants represent more than $28m lost to states, cities, non-profits and universities. It found the number of grant awards in fiscal year 2026 was 37% below the 2021 to 2024 average. Trump has also proposed cutting $1.6bn, or 26%, from Noaa's budget for next year, though many of those cuts may not survive the budget process.

Experts say the agency is also missing a chance to learn. During the last strong El Niño a decade ago, Noaa deployed planes, weather balloons, unmanned aircraft and a research ship. This year, NPR reported in September, only "a handful of unmanned watercraft" will go into the Pacific. The administration has begun removing some ocean monitoring systems and cut roughly $6bn from an investment in weather satellites, which the GAO said could create gaps in coverage. Funding for the Biogeochemical-Argo float program also expires at the end of October.

"I worry about loss of life and about our inability to be protected at a time when we need our government the most," said Monica Medina, who was principal deputy administrator of Noaa under President Barack Obama. Rick Spinrad, who led the agency under President Joe Biden, said current capabilities are strong because of past investment, but that the administration's actions suggest they will not be sustained. Noaa and the Department of Commerce did not respond to requests for comment before publication.