US States Experiencing Significant Warming

A new analysis from Climate Central demonstrates that all 50 US states have experienced rising temperatures since 1970. This report underscores the critical need to address climate change and reduce heat-trapping pollution, particularly as Earth Day is observed on April 22nd.

National Temperature Increases Since 1970

The comprehensive study examined average annual temperature shifts across 49 states and 242 major U.S. cities. The data shows the United States is warming, and the rate of warming is accelerating. The 49 states analyzed have warmed by an average of 3.0°F over the past five decades.

Alaska Leads in Warming

Alaska has experienced the most dramatic temperature increase, warming by a substantial 4.4°F since 1970. This is attributed to its high latitude, making it particularly vulnerable to climate change. New Jersey and New Mexico follow closely, both registering a 3.7°F increase.

Regional and City-Level Warming Trends

NOAA State Climate Summaries confirm warming trends across the Hawaiian Islands since 1950, with Honolulu experiencing a 2.6°F increase since 1950. States like Delaware, Massachusetts, and Vermont have also seen significant warming, with a 3.6°F increase each.

Fastest-Warming Cities

Climate Central’s research found that 240 out of 242 cities analyzed (99%) have warmed since 1970, with an average increase of 2.9°F. An impressive 85% of cities (206 total) have experienced at least 2°F of warming.

  • Southwest: 3.5°F increase
  • Upper Midwest & South: 3.2°F increase
  • Northeast: 3.0°F increase

    • The fastest-warming cities include Reno, Nevada (7.9°F), Las Vegas, Nevada (6.0°F), and El Paso, Texas (5.9°F). Burlington, Vermont, and Tyler, Texas also show significant warming at 5.3°F each.

    Rising Greenhouse Gas Concentrations

    The report’s timing coincides with unprecedented levels of heat-trapping greenhouse gases in the atmosphere. In 2025, the annual average concentration of carbon dioxide (CO2) reached 427 parts per million (ppm), a 31% increase since 1970.

    This surge is directly linked to the burning of fossil fuels – coal, oil, and methane gas – for energy, heating, cooling, transportation, and industrial processes. The resulting excess heat is driving global temperatures to rise at an alarming rate, threatening ecosystems and global stability.