February only fifth warmest; oceans hint at rising temperatures ahead
Despite a very warm start, 2025 ended up being only the third warmest year on record. This was partly due to La Niña conditions bookending the year, which helped keep the latter part of the year relatively cool.
February was the third consecutive month ranked fifth warmest on record
An HT analysis of various global temperature datasets and forecasts suggests that global temperature trends in 2026 may turn out to be the reverse of 2025. While the year has begun on a relatively cool note — with February ranking only as the fifth warmest on record — ocean temperature trends indicate that stronger warming could be on the way in the coming months.
The following three charts explain this argument in detail.
February was the third consecutive month ranked fifth warmest on record…
Daily figures for February are now final for one of the eight global temperature datasets tracked by the World Meteorological Organization (WMO): the ERA5 dataset published by the European Centre for Medium-Range Weather Forecasts (ECMWF). The data show that the average global temperature in February was exactly 1.5°C above the pre-industrial average for the month — a threshold beyond which long-term warming is expected to have catastrophic and irreversible impacts.
This makes February 2026 only the fifth warmest February on record, after February 2024, 2016, 2025 and 2020 — and the third consecutive month to rank as the fifth warmest on record.
…when the 30 months before December were ranked in the top three
A month that is 1.5°C warmer than the pre-industrial average, or ranked as the fifth warmest, does not in itself indicate cool conditions. However, the December–February period appears relatively cooler because of the extraordinary warmth that preceded it. Every month in the 30-month period from June 2023 to November 2025 ranked among the top three warmest on record.
This is what made the end of 2025 appear relatively cool — and is now having a similar effect on the beginning of 2026.
But sea surface temperatures appear to have bottomed out…
What is commonly referred to as “temperature” typically means the air temperature measured two metres above the Earth’s surface. This air temperature is influenced — with some lag — by the temperature of the surface of the world’s oceans and seas, known as sea surface temperature (SST).
Global monthly average SST data suggest that temperatures have already bottomed out. SSTs ranked among the top three warmest on record for every month from April 2023 to October 2025. They were the fourth warmest for each month from November to January, but rose to the third warmest again in February.
This provides a leading indication of where air temperatures may be headed — towards renewed warming — as rising SSTs begin to exert a stronger influence on global air temperatures.
…and equatorial Pacific conditions are also headed towards more warmth
To be sure, it is the average SST in the equatorial Pacific — rather than the global average SST — that is considered the leading indicator of changes in air temperatures. One of the most closely monitored regions in the equatorial Pacific is the Niño 3.4 region (5°N–5°S, 170°W–120°W).
According to temperature data for this region, La Niña conditions — defined as a cyclical cooling of the equatorial Pacific by at least 0.5°C, which tends to cool global temperatures — ended after mid-January. By the week ending February 18, the negative deviation had narrowed to just 0.1°C. This suggests that El Niño conditions — a cyclical warming of the equatorial Pacific Ocean of at least 0.5°C, which typically raises global temperatures — may be developing.
The official forecast from the National Oceanic and Atmospheric Administration (NOAA), a US government agency, indicates that El Niño is the most likely scenario from the July–September season through September–November. This implies that the second half of the year could see temperatures that are significantly warmer than normal.
This is the second reason why temperature trends in 2026 may appear to be the reverse of those in 2025. Unlike 2025, this year is expected to end on a warm note rather than a cool one.
