April 2026 Was the Hottest March Ever for the US Lower 48 — And El Niño Is Making It Worse

Federal data shows that March 2026 was the hottest March on record for the Lower 48 United States, by the largest margin any month has ever exceeded its record. An incoming El Niño is expected to push temperatures even higher. Here is the complete climate picture and what it means for 2026.

CBS News reported among its April 17 briefing items that 'last month was the hottest March on record for the Lower 48 states, by the most for any month ever, federal data shows.' The specific compounding of records embedded in that sentence requires parsing: this was not just the hottest March on record, but the month that exceeded its own previous record by the largest margin of any month in recorded US temperature history. No other calendar month has beaten its prior record by as large a gap.

The federal data source is the National Oceanic and Atmospheric Administration's temperature monitoring network, which covers the contiguous 48 states with the specific geographic density and historical depth that makes month-by-month temperature record comparisons meaningful. NOAA's climate monitoring function is the particular institutional foundation for claims about temperature records — its data is the specific scientific bedrock that climate reporting relies on.

The specific magnitude of the margin by which March 2026 exceeded its previous record has not been reported numerically in the available CBS coverage — the framing 'by the most for any month ever' conveys the scale without a specific number. The practical implications for American consumers: a March that broke its record by an unprecedented margin creates the specific spring season conditions whose downstream effects appear in agricultural growing patterns, water availability from winter snowpack, cooling cost projections for summer, and the particular biological systems — wildfire risk, insect populations, disease vector distributions — whose calibration to specific seasonal temperature norms creates cascading effects when those norms are exceeded.

CBS News also reported that 'a forecast El Niño could heat Earth even more' — a specific additive climate factor whose combination with the underlying warming trend that produced the March record creates the particular 2026 summer outlook whose implications for drought, wildfire, extreme heat events, and hurricane season are being actively modeled by NOAA and other federal climate agencies.

El Niño — the specific Pacific Ocean warming pattern that influences global atmospheric circulation and shifts precipitation and temperature patterns across much of the globe — historically increases global average temperatures during its active phase, particularly in the Northern Hemisphere's summer and fall. In combination with a baseline that is already breaking records by unprecedented margins, El Niño's specific additive effect creates the particular uncertainty range in 2026 summer temperature projections that emergency management, agricultural planning, and energy grid operators are managing simultaneously.

The Colorado State University 2026 hurricane season forecast, also reported by CBS on April 17, predicted 13 named storms and six hurricanes — a forecast that, in combination with the specific FEMA funding backlog reported separately, describes an alignment of elevated hurricane risk and reduced federal emergency response capacity that emergency management experts have described as particularly concerning.