The highest ever temperature recorded by the
Davis Weather Station in our back garden was
38 ℃ in July 2022. This year the mercury 'only' touched 36 ℃ on the hottest day! Mind you, we had plenty of
heatwaves early in the summer.
According to Copernicus, the last three years have been the hottest, globally, since temperature records began. 2025 was the third hottest behind 2024 (hottest) and 2023 (second hottest). Indeed, the last 11 hottest years have occurred in the past 11 years. (Figure 1). Of the two main reasons for this cluster of hottest years (2023-25), one is entirely human caused (burning fossil fuels) and the other is natural (the 2023-2024 El Nino event). A dishonourable mention also to deforestation (albeit at a slower rate) as a result of agricultural expansion and forest fires.
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| Figure 1: Global Temperature Anomalies (Copernicus) |
While global temperatures have increased by about 1.5 ℃ since pre-industrial times (i.e. after 1850), some parts of the planet are warming much faster. The Arctic is warming 3-4 times faster than the overall planet and Europe is warming about twice as fast.
In Figure 2 below, I have plotted the annual temperatures (2020 - 2025) for the United Kingdom (UK), the Central England Temperature (CET) region and our back garden in Hereford. All three temperature series have 2025 as the hottest year which is easier to visualise in Figure 3.
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| Figure 2: Annual Temperatures for the UK, CET and Hereford (2020 - 2025) |
The UK mean temperatures are lowest because it includes such far flung and cold places like Scotland where the Shetland Islands are only 400 miles south of the Arctic Circle. CET temperatures are warmer because they exclude the colder bits (like Scotland!). Hereford temperatures are the warmest, partly due to its more southerly location within the CET region and partly due to its city location where it benefits from the
Urban Heat Island Effect (UHI).
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| Figure 3: Annual Temperatures for the UK, CET and Hereford (2020 - 2025) |
The year order of mean annual temperatures (based on increasing annual temperature) are the same for the UK and CET series: 2021<2020<2024<2023<2022<2025. Hereford has a slightly different order (2021<2024<2023<2022<2020<2025) although all three series have 2021 as the coldest and 2025 as the hottest. There may be a number of reasons for this including low data granularity (only one data point for Hereford) and the coarseness of the Hereford temperature data (measured to the nearest ℃). In practice, however, the order difference is just a shift from 2020 being the second coolest year in the UK and CET series but the second warmest in the Hereford series.
2020 was the start of the COVID-19 pandemic and the implementation of lockdown procedures in the UK. I remember the clear blue skies during Spring as planes disappeared from the skies due to the 73% drop in European air passenger traffic. May 2020 was indeed one of the sunniest months on record for the UK (9.7 hours/day). Along with clear blue cloudless skies, there was also a drop in air pollution which led to a slight warming effect due to fewer cooling aerosols.
The UK Met Office reported that 2025 was the sunniest year on record for the UK. How does that compare with my sunshine records for Hereford? Figure 4 displays the estimated annual sunshine hours recorded by the Davis Weather Station located in our back garden.
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| Figure 4: Estimated Sunshine hours for Hereford City |
Although our records only go back to 2020, we can certainly confirm that 2025 was the sunniest year on record and that 2020 was the second sunniest year.
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