A historically hot March on a national scale The United States experienced its hottest March ever recorded since the beginning of measurements. Nationally, the temperature anomaly exceeded +5°C compared to normal, a considerable deviation for a monthly average. This is even the highest temperature anomaly ever observed in the United States since the beginning of measurements 132 years ago. In detail, thousands of records were broken: over 19,000 daily records and around 2,000 monthly records. This episode is not confined to just a few regions but affects a large part of the territory, from the Southwest to the Great Plains, gradually expanding eastward.
Unprecedented heat for an early start to spring in the middle of March Temperatures reached unprecedented levels for the season. In the West and Southwest, some stations recorded up to 44°C, an absolute record for March in the United States. In many cities, thermometers showed values 10 to 17°C above normal, often comparable to those at the beginning of spring. This early heat was influenced by a powerful heat dome associated with an unusually intense anticyclonic ridge over the American Southwest.
Records of heat in the United States © Meteo Consult / La Chaine Météo
Visible consequences on the environment The effects of this episode were immediate. In the western part of the country, snowfall is now significantly deficient, affecting water resources for the coming months. This situation is particularly concerning as it coincides with marked drought: nearly 60% of the territory is affected, directly impacting agriculture and water resources. Another notable consequence is a remarkable early onset of spring. In some regions, vegetation is up to a month ahead, exposing crops to increased risk in case of late frost.
A strong signal of climate change According to NOAA experts, such an event would be almost impossible today without human-induced global warming. This March is part of a series of recent records: the period from April 2025 to March 2026 is the warmest ever measured in the United States. Additionally, in the coming months, the development of a potentially strong El Niño episode could further amplify global temperature anomalies.
