22 December 2021
Tokyo Climate Center
Japan Meteorological Agency

Global temperature for 2021 to be the 6th highest since 1891
(Preliminary)
The annual anomaly* of the global average surface temperature for the year 2021 (i.e., thecombined average of the near-surface air temperature over land and the sea surfacetemperature) is estimated at +0.22°C** above the 1991 – 2020 average, likely to be the 6thwarmest on record. The past eight years (2014 to 2021) are likely to be the eight warmest
years for the 131-year period since 1891 (Figure 1).
The monthly average air temperatures for July in 2021 were the highest recorded since 1891
and May to November were ranked within the fifth warmest or higher for each month. Theseasonal average air temperature for the boreal summer (June to August) and Autumn(September to November) were also within the third highest or higher recorded since 1891 forthe season.
On a longer time scale, the annual global average surface temperature has been rising at a rateof about 0.73°C per century, which is thought to be attributed to global warming due toincrease in anthropogenic greenhouse gas concentrations including carbon dioxide. Inaddition the global averaged surface temperature is affected by inter-annual to decadal naturalfluctuations intrinsic to the earth’s climate. It is known that the global mean surface
temperature tends to decrease after a La Niña event occurs and vice versa. For this year, theLa Niña event that started in the boreal summer of 2020 ended in the boreal spring of 2021,
and a La Niña event emerged in the boreal autumn of 2021.
Warm temperature deviations are especially seen over wide areas of southern Europe andNorthern Africa to Middle East and East Asia, and the central part of North America over theland, and over the North Pacific and the Atlantic Ocean (Figure 2).
The final report on the global temperature for 2021 is scheduled to be published early inFebruary 2022.
* In May 2021, the JMA replaced the 1981 – 2010 baseline period for global monitoring with that of1991 – 2020 (See TCC News No. 65) .
** Note that this figure (hence its rank in the record, either) is still subject to change, because at themoment of this announcement it is only a preliminary result that was calculated based on temperatureobservations for the period of January to November in 2021.

Figure 1 Long-term change in annual mean surface temperature anomalies over the globe(Preliminary value)
Anomalies are derived from the 1991 – 2020 average baseline. The thin black line indicates surface
temperature anomalies for each year, while the blue and red lines indicate the related five-year runningmean and the long-term linear trend, respectively.

Figure 2 Annual mean temperature anomalies in 2021 (Preliminary value)
The circles indicate anomalies of surface temperature averaged in 5° x 5° grid boxes. The annual mean
global temperature anomaly is determined by averaging the anomalies, derived from the 1991 – 2020
average baseline, of all grid boxes weighted with the grid box area.

Ranking of annual global average temperatures

RankYear

12
3
4
5
6
7
89102016
2020
2019
2015
2017
2021
2018
2014
2010
2013

Temperature Anomaly
w.r.t. 1991 – 2020 average
+0.35
+0.34
+0.31
+0.30
+0.26
+0.22*
+0.16
+0.13
+0.11
+0.07
* 2021 is preliminariy value