The following is a summary of global temperature conditions in Berkeley Earth’s analysis of May 2020.
- May 2020 is estimated to have been the warmest May since records began in 1850.
- Updated projections for the rest of 2020 give a 89% chance that 2020 will be a new record warm year, a significant increase relative to prior projections.
Global Summary
Globally, May 2020 is estimated to have been the warmest May since records began in 1850, exceeding the previously warmest year in 2016. This follows the warmest April.
The global mean temperature in May 2020 was 0.99 ± 0.08 °C (1.78 ± 0.14 °F) above the 1951 to 1980 average.
This is equivalent to being 1.36 ± 0.09 °C (2.43 ± 0.16 °F) above the 1850 to 1900 average, which is frequently used as a benchmark for the preindustrial period.
The global mean temperature anomaly in May 2020 cooled markedly compared to April (a decrease of 0.14 °C) and was below the temperature anomaly of January through April, but still similar to values observed in November and December 2019 and among the warmest months ever observed. Due to higher weather variability during the Northern winter months, it is not unusual for the temperature anomaly in May to be somewhat smaller than those in January to March. Though the temperature anomaly is less extreme than in a few other recent months, it remains the highest temperature anomaly ever observed during May.
Spatial Variation
May 2020 continues the ongoing pattern of wide-spread warmth. Very warm conditions were again present across most of Asia, including record monthly averages for parts of central Asia. Warm conditions were also present in both the Arctic and Antarctic, as well as parts of Africa, South America, and Central America.
Unusually cold conditions were present in much of North America, Eastern Europe, India, and Australia. We estimate that 4.9% of the Earth’s surface experienced their locally warmest May average, 75% of the Earth’s surface was warmer than their long-term average, and only (0.02%) had their locally coldest May average.
Over land regions, 2020 was the warmest May, coming in as 1.45 ± 0.17 °C (2.60 ± 0.31 °F) above the 1951 to 1980 average.
May 2020 was also nominally the warmest May in the oceans, recorded as 0.61 ± 0.07 °C (1.10 ± 0.20 °F) above the 1951 to 1980 average. This is slightly warmer than the ocean average in 2015, 2016, and 2017, though the measurement uncertainties for all of these years overlap.
2020 January to May Summary
After 5 months, the Earth in 2020 has been marked by above average temperatures nearly everywhere, with especially extreme conditions across Asia. We estimate that the January to May average was record warm for 9.9% of the Earth, and appreciably above the 1951 to 1980 average for 85% of the Earth. Only, 1.5% of the Earth’s surface was significantly cooler than the 1951 to 1980 average during the current January to May period. In addition, the January to May averages for Asia, Europe, and South America all set record highs.
Looking at regions where January to May temperature averages were either the top 5 warmest or the top 5 coldest observed, we note extensive regions with record or near-record warmth to start the year and no regions of near-record cold.
The widespread record conditions in Asia during January to May 2020 warrant special consideration. In Russia, a new record average for this period was set by a very large margin, more than 1.9 °C (3.4 °F) above the previous 2016 record, and 5.3 °C (9.6 °F) above the 1951-1980 average. This is not only a record for the largest January to May temperature anomaly observed in Russia, it is also a record for the largest January to May temperature anomaly ever observed in any country’s national average.
This prolonged heat has already contributed to large early-season wildfires and the loss of permafrost.
Recently, a catastrophic oil spill involving 20,000 tonnes of diesel fuel near the Arctic city of Norilsk, Russia (within the region of record warmth) was blamed on melting permafrost that caused a storage facility to fail. Within the Arctic, it is very common for infrastructure to be built on and supported by permafrost. Warming in this region is a foreseeable risk that threatens to damage much of this existing infrastructure.
Of the first five months of 2020, only April and May have set a new record, though January to March were each no lower than the fourth warmest. Overall, the January to May average has been the 2nd warmest. The warmest January to May period occurred in 2016 and coincided with a massive El Niño event. It is remarkable that 2020 is approaching the same level of warmth despite the lack of El Niño conditions this year.
As suggested by the plot above, we would typically expect that the second half of the year to have slightly lower temperature anomalies than January to April, which is important in the context of estimating the likely range for final temperature anomalies in 2020.
However, with both April and May setting new records for monthly warmth, the projected warmth during the second half of the year remains quite high, and estimates of the likelihood that 2020 breaks the record for warmest year have continued to increase.
The statistical approach that we use now believes that 2020 has an 89% likelihood of surpassing 2016 and becoming the warmest year that has been directly measured. It is highly likely that 2020 will be one of the 2 warmest years since 1850.
However, we should note that the odds of a La Niña developing before the end of the year have also been increasing. If La Niña does occur, it will presumably push global temperatures towards the lower portion of the projected range.
Likelihood of final 2020 ranking, based on January to April:
- 1st place (89%)
- 2nd place (10%)
- Top 2 overall (>98%)
As noted above, unusual recent conditions have shifted the current projection for 2020 to be significantly higher than previous projections issued earlier this year.
