ESOTC 2022 | EUROPE

Temperature

Surface air temperature, referred to from here on as ‘temperature’, has large impacts on both human and natural systems. It affects health, agriculture and energy demand, for example, as well as growth cycles in natural environments. Human health is especially affected by extreme temperatures^[1]. Information on unusually warm periods in 2022 can be read in the ‘Extreme heat’ section.

In addition to air temperatures, water temperatures are important to monitor, as both indicators and regulators of climate change. Sea surface temperatures and lake surface water temperatures are both discussed in the ‘Lake and Sea Temperatures’ section.

Figure 1. Annual European land surface air temperature anomalies for 1950 to 2022, relative to the 1991–2020 reference period. Data source: ERA5 and EOBS. Credit: C3S/ECMWF/KNMI.
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Temperatures for Europe as a whole show long-term warming trends for both annual and seasonal averages. The trends are not uniform over time, however, and generally show little change, or weak cooling, from the 1950s to the 1980s, and the majority of the warming thereafter. The annual average temperature shows that 2022 was warmer than the average for the 1991–2020 reference period, by 0.85–0.87°C^[2]. The annual temperature for 2022 was the second warmest on record for Europe, and was 0.3°C cooler than 2020, the warmest year on record. The ten warmest years on record for Europe have all occurred since 2000, and the five warmest years have all occurred since 2014.

More information on the longer-term perspective can be found in the ‘Temperature indicator’ section.

Temperatures for the year as a whole were above average across most of Europe. The largest anomalies occurred in the southern, western and some eastern parts of the continent, and northern Scandinavia, with some areas in southwestern Europe seeing temperatures up to 2.5°C above average. Small negative anomalies occurred in Türkiye and Iceland, with temperatures as much as 0.75°C below average.

During 2022, winter, summer and autumn were all warmer than the respective seasonal averages. Summer 2022 was the warmest on record, at 1.4°C above average^[3]. It was 0.3–0.4°C above 2021, the second warmest summer on record, and 0.5°C above the third and fourth warmest summers on record, 2010 and 2018, which differed by less than 0.05°C.

Winter and autumn both saw large positive anomalies, of 0.9°C and 1.0°C respectively. Winter was the seventh to ninth warmest on record, depending on the dataset, and autumn the third warmest. While these seasons were less exceptional than summer, they were still warmer than the vast majority of their respective seasons in the long-term records. Spring saw a small negative anomaly of -0.1 to -0.2°C.

In winter, much of Europe saw temperatures more than 1°C above average, although in northern Scandinavia and Iceland, temperatures were as much as 1°C cooler than average. The largest anomalies were found in central Europe, where temperatures were around 2.5°C above average, and in eastern-most parts of Europe, where temperatures reached 3.5–4°C above average.

During spring, Scandinavia and western Europe experienced temperatures close to or slightly above average, while much of eastern Europe experienced temperatures around 1.5°C below average. The lowest temperatures were found in northwestern Russia, with negative anomalies of -2°C across a large area and -2.5°C in a smaller region in the northeast of the domain.

In summer, most of Europe, except Iceland and Türkiye, saw temperatures much above average. Across much of the southwest, temperatures were more than 2°C above average, with some small regions in the southwest seeing anomalies that reached 4°C.

Autumn saw temperatures close to average in northeastern Europe, while across much of northern, western and southern Europe, temperatures were 1–3°C warmer than average, with the largest anomalies in southwestern France, and southern and eastern Spain.

Figure 5. Average surface air temperature anomalies for each month of 2022, relative to the respective monthly average for the 1991–2020 reference period. Data source: ERA5. Credit: C3S/ECMWF.
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Warm spells were seen in March, May, summer, October and December, affecting different regions of Europe. These are reflected in the large positive monthly temperature anomalies, and are discussed in more detail in the ‘Extreme heat’ section. August and October 2022 were the warmest on record, June was the second warmest, and November and July were fifth and sixth warmest on record, respectively^[4].

Negative anomalies occurred in southern and eastern Europe in March, northeastern Europe in May and September, and northwestern Europe in December. The contrast in December is most striking, with southern Europe much warmer than average, and northern Europe much colder than average. Despite some regions seeing below-average temperatures, no months in 2022 were ranked as particularly cool compared to the long-term record^[4].

The large-scale circulation patterns associated with these monthly temperature anomalies are discussed in the ‘Atmospheric circulation’ section, and further implications for power production are mentioned in the ‘Renewable energy resources’ section.

Figure 6. Average daily European land surface air temperature anomalies for 2022, relative to the average for the 1991–2020 reference period. The black lines show the 10th and 90th percentiles of the daily European land surface air temperature over 1991–2020. Data source: E-OBS. Credit: KNMI.
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The fluctuations in daily temperatures also highlight that, while there were periods of above- and below-average temperatures lasting several days or weeks, Europe was warmer than average for most of the year, and there were several periods of well-above average temperatures during summer and autumn. These periods are discussed in more detail, alongside health aspects and the wider context, in the ‘Extreme heat’ section.

While some regions saw negative anomalies in certain months (Figure 5), there were many more warm than cool events in 2022, with just one brief period in April during which Europe as a whole was much cooler than average, and a longer period of below-average temperatures in late autumn into winter. In December, a cold spell affected northern Europe and, in particular, the United Kingdom (UK), Scandinavia and Iceland. In Iceland, the capital Reykjavik recorded its lowest temperature since 1918^[5], and the UK saw one of the most significant spells of low winter temperatures since December 2010^[6]. This cold spell is also discussed in the ‘Atmospheric circulation’ and ‘Renewable Energy Resources’ sections.

Figure 7. Annual mean anomaly of daily minimum (left) and maximum (right) surface air temperature for 2022, relative to the 1991–2020 reference period. Data source: E-OBS. Credit: C3S/ECMWF/KNMI.
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In addition to the annual, seasonal and daily temperatures, the average daily minimum and maximum temperatures for each season, and for the year as a whole, are of importance. They give an indication of the extreme ends of the daily temperature cycle, revealing whether there were unusually cool or warm nighttime and daytime temperatures.

In 2022, across almost the entirety of Europe, both minimum and maximum temperatures were much above average. Minimum temperatures were up to 1°C above average across most of Europe, and up to 3.5°C above average in parts of Italy and France, while northern Scandinavia also saw minimum temperatures between 2 and 2.5°C above average.

Almost all of Europe experienced maximum temperature anomalies of more than 1°C during 2022. Maximum temperature anomalies were highest in France and some neighbouring areas, such as northeastern Spain, with anomalies of 2.5°C, and up to 4°C in some areas.

The seasonal anomalies (Figure 8) of maximum and minimum temperatures follow similar patterns and amplitudes to the anomalies in average temperature for each season (Figure 4). Some parts of southwestern Europe in winter saw slightly below-average minimum temperatures, with above-average maximum temperatures, while in Italy in summer, minimum temperatures were much above average while maximum temperatures were close to or slightly below average. Temperature extremes are discussed in more detail in the ‘Extreme heat’ section.

Figure 8. Seasonal mean anomalies for winter, spring, summer and autumn 2022 of daily minimum (left) and maximum (right) surface air temperatures, relative to the respective seasonal average for the 1991–2020 reference period. Winter values relate to December 2021 – February 2022. Data source: E-OBS. Credit: C3S/ECMWF/KNMI.
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Notes

[1] Surface air temperature is one of the 54 current GCOS 'Essential Climate Variables' (ECVs). In addition to the immediate impacts of surface air temperature, as outlined in the introduction, its global average is also a target measure for the Paris Agreement. To read more about this, visit the ‘Temperature indicator’ section.

[2] ERA5 and E-OBS temperature datasets and their differences:

For this section, two temperature datasets were used for the analysis: ERA5 and E-OBS. To increase readability, maps of both are shown in tab format.

When temperature ranges are given for time series statistics, this is to indicate the range between the datasets.

Though the two datasets used here agree in general, both for spatial averages (such as Figure 1) and across the European domain, there are some differences that can be seen, mainly due to reasons described below.

Differences due to data coverage of underlying stations

For both ERA5 and E-OBS, the observational coverage varies in both space and time and affects the uncertainty - a larger amount of higher quality observations reduces the uncertainty. The potential for disagreement between the two datasets is larger when one or both suffer from higher uncertainty. For E-OBS, observational coverage is relatively poor, and uncertainty is higher, in the following regions:

Southern Balkans, Greece, Iceland and Türkiye

Generally, data coverage is lower in these regions than for other parts of the E-OBS dataset. For these regions, the uncertainty is assessed and where that uncertainty is deemed to be unreasonably high, the data values are not shown.

Northern Africa and other regions at the boundaries of the E-OBS domain

The generally limited number of stations at the boundaries of the E-OBS domain (the region with values in the E-OBS maps), for example in northern Africa, and the difficulty of interpolating along the boundaries of the domain, means that estimates in these regions are less reliable and more uncertain than in others.

Differences due to the character of the dataset

ERA5 blends observational data from many conventional and satellite sources with model forecasts at a relatively coarse spatial resolution. E-OBS draws information directly from in situ stations. Therefore, particularly in regions with complex topography, such as the Alps, E-OBS is likely to provide a more accurate estimate than ERA5. Further, for its estimates of minimum and maximum temperatures, E-OBS interpolates the actual minimum and maximum temperatures observed at the meteorological stations. The relatively poor spatial and temporal resolution in ERA5 may lead to an underestimation of temperature extremes at both ends of the distribution, and therefore the E-OBS anomalies are used here.

[3] Based on the rounded average of the two datasets, ERA5 (1.339°C) and E-OBS (1.359°C).

[4] Based on ERA5 data going back to 1950.

[5] Record low temperatures in Iceland discussed by the UN and WMO: unric.org/en/wmo-2023-off-to-warm-start-breaking-records-in-europe

[6] A UK Met Office review of the UK’s climate in 2022: carbonbrief.org/met-office-a-review-of-the-uks-climate-in-2022