January 2025 Breaks Global Heat Record Despite La Niña, Marking 18th Month Above 1.5°C Threshold

C3S reported that January 2025 was the 18th month in the last 19 months where the global-average surface air temperature exceeded 1.5°C above pre-industrial levels.

Global Temperature Records and Anomalies

January 2025 set a new global temperature record, marking it as the warmest January ever recorded, according to the Copernicus Climate Change Service (C3S) and the US National Oceanic and Atmospheric Administration (NOAA). The month was 1.75°C above pre-industrial levels, surpassing January 2024, which occurred during an El Niño event known for warming trends. This record is notable as it occurred during a La Niña event, which typically brings temporary cooling.

C3S reported that January 2025 was the 18th month in the last 19 months where the global-average surface air temperature exceeded 1.5°C above pre-industrial levels. Despite slight variations between datasets, all sources confirm an ongoing streak of record-breaking global temperatures.

Regional Climate Anomalies and Sea Ice Decline

Global temperatures were above average in most regions, though much of the United States, Greenland, and far eastern Russia experienced below-average temperatures. The Arctic saw joint-lowest sea ice extent on record for January (C3S) and the second-lowest according to NOAA.

Sea surface temperatures were above average globally, with exceptions in the central and eastern tropical Pacific, consistent with La Niña conditions. NOAA's Climate Prediction Center stated that La Niña conditions began in December 2024 and are expected to continue through April 2025.

Precipitation and Extreme Weather Events

January 2025 saw below-average rainfall across much of the contiguous United States, Mexico, Central America, southeastern Europe, southwest and central Asia, parts of southeast Asia, and Australia. Conversely, wetter-than-average conditions affected regions from western to northeastern Europe, central and eastern Asia, and southeastern Russia.

Southern Brazil and central Java, Indonesia, experienced severe flooding and landslides following heavy rainfall, resulting in significant damage and fatalities.

Five named storms formed globally during the month, below the average of seven. The most impactful was Intense Tropical Cyclone Dikeledi in the southwestern Indian Ocean, causing destruction in Madagascar and Mozambique.

Global Climate Trends and Outlook

2024 was the warmest year on record, with global temperatures temporarily surpassing 1.5°C above pre-industrial levels. Despite a single-year breach not constituting a failure of the Paris Agreement goals, the trend underscores the urgency of climate action, as each fraction of a degree of warming has significant consequences.

The World Meteorological Organization (WMO) is expected to release its next El Niño/La Niña update in early March.