Weather Bee | 2024 warming is 1.6°C in ERA5 data
The daily ERA5 data also shows that 2024 has had 274 days when warming relative to the pre-industrial average was at least 1.50°C
The year 2024 was the first during which the average global temperature exceeded the pre-industrial level by more than 1.5°C in multiple datasets. Data released on January 10 shows warming in the the ERA5 data was 1.6°C, as this analysis had suggested on January 2.

Data up to November makes it almost certain that the average global temperature will show a warming of 1.5°C or more relative to the pre-industrial average in at least three datasets. That will make 2024 the first year in two of them and the second year in one dataset to breach the 1.5°C threshold, which is expected to lead to catastrophic climate change if it persists long-term. The only question that December data will answer is the amount by which different datasets cross this threshold. For one of those datasets, the warming in 2024 could be close to 1.60°C, preliminary data up to December 31 shows.
Of the five datasets analysed by HT, ERA5, the data produced by the Copernicus Climate Change Service (C3S), is one of the three that is almost certain to breach the 1.5°C threshold in 2024 (more on this here). Since C3S also publishes preliminary daily data from ERA5, it is possible to analyse the level of warming 2024 is headed to, since only the data for December 31 remains to be finalised.
Daily ERA5 data up to December 31 shows that 2024 is 1.599°C warmer than the pre-industrial average in this data. This would make 2024 the warmest year ever and the first year to breach the 1.5°C threshold in ERA5 data. Last year, ERA5 data had shown a warming of 1.48°C compared to the pre-industrial average. To be sure, all ERA5 numbers must be read because they are among the datasets that show somewhat higher warming than others.
To be sure, December 2024 is likely to average a warming of “only” 1.69°C. This will make December last year the second warmest after December 2023. December 2023 had shown a warming of 1.78°C.
December being ranked second warmest this year is in line with a gradual cooling (compared to 2023) seen from July. Each month from July onwards (except August) is ranked the second warmest this year after 2023. This is because a periodic warming of the equatorial Pacific Ocean – called El Nino -- had given a bump to global temperatures in the latter half of 2023 in addition to global warming. While El Nino ended in May, temperatures have been slow to cool down, only cooling marginally compared to 2023. With the first half of 2024 much warmer than 2023, the small level of relative cooling in the latter half has not helped 2024 cool down compared to 2023 overall.
The daily ERA5 data also shows that 2024 has had 274 days when warming relative to the pre-industrial average was at least 1.50°C, far ahead of 173 such days recorded in 2023. To be sure, 2023 had more days that saw at least 1.75°C warming: 54 compared to 50 in 2024 so far.
These relative comparisons with 2023, however, should be read with the fact there was no day of 1.5°C warming in the ERA5 data before 2015. The record number of such days experienced in 2023 and 2024 only highlight the accelerated rate of global warming in recent years.
Abhishek Jha, HT’s senior data journalist, analyses one big weather trend in the context of the ongoing climate crisis every week, using weather data from ground and satellite observations spanning decades.
