Weather Bee: January 2026 only the fifth warmest January on record

In a time when temperatures appear to be breaking past records every other month, January 2026 is only the fifth warmest January month on record.

The high levels of global warming seen in 2023 and 2024 – the two warmest years on record so far – means that any relief, even if temporary, is welcome. Global temperature data for January, available now from one of six temperature data sets tracked by the World Meteorological Organization (WMO), shows that 2026 has started with a relief of that kind.

January temperatures averaging fifth warmest has also prolonged the cooling spell that started in December. (AFP)

In a time when temperatures appear to be breaking past records every other month, January 2026 is only the fifth warmest January month on record. This relatively low level of warming in itself is a kind of record, an HT analysis shows, compared to how temperatures were behaving in the past two and half years. However, this relief is still just a cyclical blip. Here is how.

According to the ERA5 global temperature data published by the Copernicus Climate Change Service (C3S), January 2026 averaged a warming of 1.47°C relative to the pre-industrial average. This is significantly cooler than the 1.75°C and 1.66°C warming recorded in January in 2025 and 2024, the two warmest January months on record; and also somewhat lower than the 1.54°C and 1.51°C warming recorded in 2020 and 2016, the next two warmest January months on record.

January temperatures averaging fifth warmest has also prolonged the cooling spell that started in December. December 2025 was also ranked the fifth warmest December month on record. This is the first time since April-May 2023 – a gap of two and a half years – that two consecutive months have not been ranked among the top three warmest relative to the same month in previous years.

To be sure, neither are the trends described above unexpected, nor are they cause for much celebration. The latter can be seen even by reading January numbers. A warming of 1.47°C is still very close to the 1.5°C threshold. Besides, daily global averages breached the 1.5°C threshold on 15 of the 31 days in January.

The 1.5°C threshold is important because scientists believe that the world is moving towards the point where the long-term average of global temperatures will breach it; which can lead to catastrophic and irreversible change in global climate. A daily or monthly number close to the threshold does not help in pulling that long-term average sufficiently down.

The reason why January temperatures averaged lower compared to the past two years also undermines its impact on long-term trends. The reason was a cyclical cooling of the equatorial Pacific Ocean – called La Nina – that has a cooling effect on global temperatures. This can be seen in the value of the Oceanic Nino Index (ONI), which was largely -0.5 or lower after the first week of October to the middle of January. Since La Nina affects global temperatures with a lag of two-four months, a cooling was somewhat expected in December and January.

Oceanic Nino Index for the Nino 3.4 region

In contrast to January 2026, the October-December periods preceding the years when January was warmer than in 2026 were affected by either an El Nino (a cyclical warming of the equatorial Pacific Ocean that warms up global temperatures) or recovering from an El Nino. In other words, January 2026 has managed to record warming close to some of the warmest January months despite the former facing favourable conditions for cooling and the latter unfavourable.

To make matters worse, the current cyclical spell of La Nina is not expected to last. Forecasts for El Nina, La Nina, and neutral conditions (neither El Nino nor La Nina) are generally made in terms of three-month averages. The most recent forecast shows that the three months ending March are more likely to be in neutral conditions than in La Nina conditions; and El Nino is the most probable event from the three-month period ending August. This means that the second half of the year is likely to undo the benefits of cyclical cooling seen in January. This is why the relief in January, even if it were to continue for a couple of months beyond, is only a brief pitstop in the ongoing long march of global warming.