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UK Climate in 2021

UK Climate in 2021 12 January 2022

Met Office: A review of the UK’s climate in 2021 (via Carbon Brief)

As 2021 came to a close with a record New Year’s Eve high temperature for the UK, 2022 started in a similar fashion with its own record high for New Year’s Day.

Despite the record–breaking turn of the year, a look back at 2021 reveals a fairly average year for the UK’s weather – especially compared to the dramatic and memorable conditions of 2020. 

However, “average” in today’s climate is still the UK’s 18th warmest in a record stretching back to 1884.

In this review, we unpack the UK’s climate in 2021 – for the year as a whole and each individual season. Our analysis also shows that the likelihood of seeing a year as warm as 2021 in a world without climate change is just 2.5% – but could be as likely as 89% by the end of the century.

Shifting baselines

Was 2021 an average year for UK climate? The answer rather hinges on what we define as “average” – a rather tricky concept in a shifting climate. 

All national meteorological agencies, including the Met Office in the UK, retain extensive historical records of weather and climate observations. In order to facilitate international consistency in the way these statistics are reported, the World Meteorological Organization provides guidance on climatological best practice. 

These define “reference” climatological periods as being the most recent 30–year period commencing with a year ending in “1”. The current reference climate period has, therefore, recently been updated to 1991–2020, replacing the previous reference period of 1981–2010. For long–term climate monitoring, 1961–1990 is also retained as a standard.

The UK mean temperature for 2021 was 9.28C. This is a mere 0.12C above the 1991–2020 reference period, making it a decidedly “average” year in comparison to the climate of the recent past. 

The maps below show average temperature (left), rainfall (middle) and sunshine duration (right) compared to 1991–2020, across the UK last year. Rainfall was slightly below average overall – particularly for north and west Scotland – and sunshine was slightly above average in the north and west and below in the southeast of the UK. 

Read the full story from Carbon Brief here.