Updated: 2026-08-05
The summer of 1976 in London — the one your parents still talk about — reached a mean maximum temperature of 25.6°C across June, July and August. That figure was tied in 2022, when the 25.6°C mark was matched again at St James's Park. The summer of 1912, by contrast, sat at just 19.9°C — a gap you can feel on your skin. But the story is not a simple line upward: the hottest year in the record is not a recent one, and the coldest summers are spread across the whole century.
If you grew up in London in the 1970s or 80s, your memory of long, hot summers is not a trick of nostalgia. The data from the Met Office's MIDAS archive at St James's Park — London's longest continuous weather station — shows that summer mean maximum temperatures have shifted, but the shift is more nuanced than a simple "it was better then." Some of the warmest summers on record for the capital occurred in the 1930s and 1940s, decades before you might expect.
Take 1947, for example. The summer mean maximum at St James's Park reached 23.8°C — not as warm as 2018's 25.3°C, but warmer than 1991's 21.4°C and 1992's 22.3°C. And 1933 hit 23.7°C, the same value as 2019 and 1959. The idea that all modern summers are uniformly hotter than all old ones does not hold up against the full record.
What the data show more clearly is a clustering: the coolest summers tend to appear in the early decades, while the warmest cluster in the most recent ones. The summer of 1912 at 19.9°C and 1920 at the same 19.9°C sit near the bottom of the table. In between, there are cold outliers like 1954 at 19.3°C and 1956 at 19.4°C — the two coolest summers in the entire 1912–2025 series.
No summer in the London record tops 25.6°C for mean maximum temperature. That value appears twice: in 1976 and in 2022. The proximity of 2022 to the present — and the fact that 2025 reached 25.0°C — tells you that the latter half of the 2010s and the 2020s are producing summers that rival, and sometimes match, the famous heat of the mid-1970s.
But note the years in between. The summer of 1975, just before the famous one, reached 23.6°C — the same as 1989, 1949 and 1975 itself. The summer of 1983 hit 24.0°C, a value not seen again until 2006's 24.3°C and 2018's 25.3°C. So the "great summers" of memory are real, but they are peaks in a record that has always had warm summers at intervals.
For the standard reference period 1991–2020, the mean daily maximum temperature across all of Greater London — averaging all stations in the area — sits at 15.4°C, with a mean daily temperature of 11.5°C. That is the full-year average, not just summer. Compare that to the summer-only values in the table below, and you see how much of London's annual warmth is concentrated in June, July and August.
The table below shows the mean maximum temperature for each summer (June–August) at St James's Park. Scan it and you will see the 1920s and 1930s producing values in the low 20s, the 1970s peaking, and the 2000s and 2010s clustering increasingly toward the mid-20s. The series runs continuously from 1912 to 1999, and then again from 2004 to 2025; the early 2000s are the only gap in the station record.
The chart shows the complete annual series. The table lists the most notable years; the full series comes from Met Office.
| Year | Summer mean max (°C) |
|---|---|
| 1954 | 19.3 |
| 1976 | 25.6 |
| 1995 | 24.6 |
| 2006 | 24.3 |
| 2018 | 25.3 |
| 2022 | 25.6 |
| 2025 | 25.0 |
If you want a quick read of the extreme end of this record, these five years tell the story:
Notice that the coolest summers are all clustered in the 1950s, while the warmest appear in 1976 and 2022. But the 1930s and 1940s also produced summers that would not look out of place today: 1933 at 23.7°C, 1947 at 23.8°C, and 1949 at 23.6°C are all within a fraction of the 2010s and 2020s values.
So were summers really better when you were young? The honest answer from the St James's Park record is: it depends on when you were young. If you were a child in the 1950s, your memory of cool, grey summers is accurate — 1954 and 1956 are the coldest in the whole 1912–2025 series. If you grew up in the 1970s, you experienced 1976, which remains tied for the warmest summer ever recorded in London. And if you are under 25, your reference point includes 2022's 25.6°C and 2025's 25.0°C — both warmer than anything your grandparents saw in the 1930s, except for 1933 and 1947.
The record does not show a steady climb. It shows warm summers recurring: 1921, 1933, 1947, 1949, 1959, 1975, 1976, 1983, 1989, 1995, 2006, 2018, 2022, 2025. The frequency of very warm summers — those above 23.0°C mean maximum — increases noticeably after 1989. In the 60 years from 1912 to 1971, there are only a handful of such summers. In the 54 years from 1972 to 2025, there are many more, including the two hottest on record.
Data source: Met Office MIDAS archive, St James's Park, London (1912–2025). Summer values are mean daily maximum temperatures for June–August. Full series available through the Met Office National Climate Information Centre.
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