Updated: 2026-08-15
If you want to know which year sits at the top of London's rainfall ranking over the last half-century, the answer arrives with a distinctly 1980s signature. 1987 holds the number one position, with a total annual rainfall of 723.5 mm recorded at the Met Office's London St James's Park station. That figure places 1987 as the wettest year in the 50-year window running from 1975, drawn from the station's complete observational record.
Total annual precipitation in 1987 – the peak year of the last 50 years in London.
The ranking comes from the Met Office's long-running weather station at St James's Park, a site that has been keeping a continuous watch over the capital's climate since the early 20th century. The full series available at this location spans from 1 January 1912 to 31 December 2025, giving researchers and weather enthusiasts a remarkably deep archive of daily readings. When scanning the most recent 50 years of that record, excluding any provisional data that might skew the picture, 1987 emerges as the standout year for rainfall.
What makes 1987 particularly notable is that it sits within living memory for many Londoners. The year carried the infamous Great Storm of October, which brought widespread disruption to the south-east of England. While that single event did not alone define the entire year's rainfall, the annual total of 723.5 mm reflects a sustained pattern of wet weather across the calendar. The fact that no subsequent year, including the very wet winters and summers of the 2000s and 2010s, has pushed more rain through the gauge at St James's Park speaks to how exceptional that accumulation was.
To place any individual year in context, meteorologists rank the annual totals from the period in question. Over the last 50 years of data at this station, the years are ordered from driest to wettest. The year that accumulates the most rainfall, 1987 with its 723.5 mm, sits at the 100th percentile of that distribution. This means that every other year in the 50-year window received less precipitation than 1987 did. The percentile ranking is a straightforward way to communicate where a particular year falls compared with its neighbours, without needing to compute long-term averages on the fly.
Because the dataset at St James's Park extends back to 1912, the 50-year window itself is a subset of a much longer observational record. That longer perspective matters: it allows us to see whether recent rankings are exceptional in the broader historical context of London's climate, or whether they fall within a range that earlier decades also experienced.
The monthly breakdown for the station reveals how rainfall is distributed through the year, based on the entire period of records from 1912 through 2025. While the annual ranking highlights 1987 as the wettest single year in the last 50, the monthly totals below show which parts of the calendar tend to carry the most precipitation across the full series. These values represent the total rainfall measured for each month over the complete period of available data. Note: the monthly figures display cumulative totals for the entire period (1912–2025), not monthly averages for a single year.
| Month | Mean temperature (°C) | Mean max (°C) | Mean min (°C) | Total rainfall (mm) | Wettest year (rainfall, mm) |
|---|---|---|---|---|---|
| January | 5.2 | 7.7 | 2.8 | 2655.9 | 2014 (142.8) |
| February | 5.5 | 8.2 | 2.8 | 1765.6 | 1990 (185.2) |
| March | 7.5 | 10.9 | 4.1 | 2243.1 | 1981 (211.8) |
| April | 10.0 | 13.9 | 6.0 | 2279.2 | 2012 (166.0) |
| May | 13.4 | 17.7 | 9.1 | 2265.0 | 2024 (150.4) |
| June | 16.3 | 20.8 | 11.9 | 2424.5 | 2016 (158.6) |
| July | 18.3 | 22.6 | 14.0 | 2346.9 | 1987 (133.2) |
| August | 18.0 | 22.3 | 13.8 | 2883.7 | 2025 (175.4) |
| September | 15.7 | 19.7 | 11.7 | 2626.1 | 1987 (168.0) |
| October | 12.1 | 15.5 | 8.8 | 2706.6 | 1993 (164.2) |
| November | 8.1 | 10.9 | 5.3 | 2709.8 | 2015 (201.6) |
| December | 6.1 | 8.6 | 3.6 | 2687.2 | 2015 (176.2) |
The monthly table shows August as the month with the highest total rainfall accumulation across the entire available period, with 2883.7 mm. February stands at the opposite end with 1765.6 mm, the lowest monthly total in the table. It is worth noting that these are cumulative totals over 114 years of records, not an average for any single year. They illustrate how the station's long-term observational series distributes precipitation across the seasons, with late summer and autumn months generally carrying larger totals than late winter.
For anyone investigating London's wet years, the path leads to 1987. Its 723.5 mm annual total ranks it first among the last 50 years, meaning that in the period from 1975 onward, no other year has produced more rainfall at St James's Park. The station itself, a core component of the Met Office's network, provides the authoritative record for this ranking, and its data spans a period that allows the 50-year comparison to sit within a much larger observational context.
The full series from 1912 to 2025 offers a long lens through which to view annual rainfall in the capital. Weather patterns fluctuate naturally from year to year, but the persistence of 1987 at the top of the ranking over five subsequent decades demonstrates that a single-year accumulation of that scale remains a rare occurrence in London's recent climate history.
Source: Met Office – London St James's Park station. Data period: 1912–2025.
HistoClima Tools: discover the weather on the day you were born, your wedding day, or your birthday-week statistics.
AI-assisted content from official Met Office data, automatically verified. 🤖 IA-assisted content · Art. 50 EU AI Act
© 2026 HistoClima · data: Met Office (OGL v3.0) · not affiliated with Met Office · citation permitted with source.