Earth Experiences Steady Stream of Heat Records

Heat records have become commonplace in meteorological record-keeping, while new cold records have become few and far between. According to data from the National Centers for Environmental Information at the National Oceanic and Atmospheric Administration, more than 7 percent of the Earth's surface experienced new mean monthly temperature records this May, meaning that the average temperature was the highest for the respective time and location ever recorded.

Mean monthly temperature records reached highs in the past three years in September of 2023, when around 20 percent of the Earth's surface set new mean temperature records for that month, and in April and June of 2024, when this applied to more than 14 percent of the globe. The biggest month for cold records in the same time frame was January 2024. However, a much smaller 0.9 percent of Earth's surface set new records for the lowest mean monthly temperatures ever recorded.

Looking back further, new heat records used to be far less common than new cold records, with the balance flipping for almost all months in the past decades. In May, the most recent month on record, new cold record were much more common in the 1950s, 60s and 70s, before new heat records became the norm by a large margin from the 2000s onwards.