Four things, measured year by year: how much rain fell, how often rivers
reached a level they rarely reach, how often flood alerts went out, and how often sewage
overflows spilled. For the UK.
Three of these four are counted better every year, so the raw numbers
climb whether or not the weather does. Flood alerts have risen steeply since 2006 — and so
has the number of places that can be sent one. Every chart below divides by what changed,
and says underneath it exactly what it divided by.
Rainfall is UK-wide, the river gauges are Great Britain, and flood
alerts and sewage are England only — that is as far as the Environment Agency's records go.
Only whole calendar years are shown, so the year we are in appears once it has finished.
So far in 2026
1 January to 26 October, in every year below
Every other chart on this page waits for a year to finish, because
half a year is not comparable with a whole one. These two do not: each bar covers
1 January to 26 October
— the same stretch in every year of the record — so 2026 can be read
against the others now, without waiting for December.
Flood alerts and warnings, so far this year
2026 so far: 5.21 per area — the highest of the 21 years we hold for this stretch of the calendar, and 58% above the average of the last 10 years over the same stretch.
El Niño winter La Niña winter. Marked for context, not as a cause — these are states of the Pacific, and one wet fortnight moves a British year more than a whole season's pattern does. What El Niño and La Niña are, and what they did here.
The raw count went from 1,076 to 5,069 alerts and warnings between 2006 and 2026, while the areas warned went from 280 to 973 — which is what the chart divides by.
Every bar here covers the same stretch of the calendar — 1 January to the same date — so the year we are standing in can be compared with the ones before it without waiting for December. It is still divided by the areas actually warned, so the growing register cannot move it. A wet fortnight in one season can carry a whole year, and the rest of this year has not happened yet.
River gauges reaching a high level, so far this year
2026 so far: 36.8% — 14th highest of the 37 years we hold for this stretch of the calendar, and 11% below the average of the last 10 years over the same stretch.
El Niño winter La Niña winter. Marked for context, not as a cause — these are states of the Pacific, and one wet fortnight moves a British year more than a whole season's pattern does. What El Niño and La Niña are, and what they did here.
The raw count went from 171 to 1,095 gauges with a high day between 1990 and 2026, while the gauges reporting went from 525 to 2,979 — which is what the chart divides by.
The same stretch of the calendar in every year — 1 January to the same date — so this year can be read against the others before it has finished. It carries the same ceiling as the whole-year chart above: each gauge is measured against the level it itself reaches about one day a year, so this finds years when high days bunched, not whether rivers run higher than they did.
Rainfall and sewage cannot be shown this way. The Met
Office areal series is published once a year, and our own daily rain-gauge record is a
different measurement with gaps in its earlier years — putting the two side by side would
be exactly the arithmetic this page exists to avoid. The Environment Agency publishes
sewage returns once a year and has not yet published 2026.
Rainfall
United Kingdom, Met Office areal rainfall, 1926–2025
The last 50 years average 1,150mm, against 1,067mm for the first 50 — 7.8% higher.
El Niño winter La Niña winter. Marked for context, not as a cause — these are states of the Pacific, and one wet fortnight moves a British year more than a whole season's pattern does. What El Niño and La Niña are, and what they did here.
The one series here that needs no adjusting: the Met Office has measured areal rainfall the same way since 1836, so a tall bar is a wet year and nothing else. It is an average over a whole region, not a reading from your street.
River gauges reaching a high level
Great Britain, Environment Agency, SEPA and NRW gauges, 1990–2025
The last 18 years average 47.4%, against 35.8% for the first 18 — 32% higher.
El Niño winter La Niña winter. Marked for context, not as a cause — these are states of the Pacific, and one wet fortnight moves a British year more than a whole season's pattern does. What El Niño and La Niña are, and what they did here.
The raw count went from 179 to 1,759 gauges with a high day between 1990 and 2025, while the gauges reporting went from 528 to 2,985 — which is what the chart divides by.
Each gauge's high level was last re-fitted on 31 October 2026, over that gauge's whole record. It is re-fitted monthly, so these percentages can move a little between rebuilds even in a week with no rain.
What this chart finds is BUNCHING — years when many gauges reached their own high level at once. It cannot tell you whether rivers run higher than they used to, and here is why: each gauge is measured against the level it itself reaches about one day a year over its own whole record, so every gauge crosses that bar about once a year by construction, however wet or dry its river has become. The bar is re-fitted every month as records grow, so a wet decade raises it and damps the very rise you are looking for. Dividing by the gauges that reported keeps the growing fleet out of the count; the like-for-like chart below holds the gauges themselves fixed as well.
The same gauges, every year
The last 12 years average 51.8%, against 38.8% for the first 12 — 34% higher.
The raw count went from 110 to 217 gauges with a high day between 2001 and 2025, divided every year by the same 324 gauges in the panel — which is what makes the two ends comparable.
The strictest read: the SAME gauges every year, each reporting nearly every day of every year in the window, so neither the fleet nor the length of record behind each high level can move underneath the line. A few hundred long-serving gauges rather than the whole fleet, so it is a narrower sample of the country than the chart above. One thing it does NOT fix: the bar is still each gauge's own once-a-year level, so this too shows when high days bunched, not whether the river runs higher than it did.
Little changed: the first 10 years average 3.87 per area and the last 10 average 4.05 per area — 4.6% higher.
El Niño winter La Niña winter. Marked for context, not as a cause — these are states of the Pacific, and one wet fortnight moves a British year more than a whole season's pattern does. What El Niño and La Niña are, and what they did here.
The raw count went from 2,241 to 4,249 alerts and warnings between 2006 and 2025, while the areas warned went from 416 to 1,279 — which is what the chart divides by.
Raw warning counts have risen steeply since 2006, but so has the number of flood areas that can be warned at all. This chart divides by the areas actually warned, which is the part that is about the weather rather than about the register. Warning policy also changed over the period.
2021: 29.4 spills. 2025: 20.6 spills — 30% lower. That is two years compared, not a trend: the years in between jump about more than the difference between these two.
The raw count went from 319,807 to 290,430 spills between 2021 and 2025, while the monitored overflows went from 10,871 to 14,101 — which is what the chart divides by.
Only five years exist, so this is a comparison and not a trend. The number of monitored overflows grew across them, which is why the figure is per overflow. Spills also track the weather: 2022 was a drought summer, and it is one of only five years here, so it pulls the comparison about on its own.
The same overflows, every year
2021: 29.3 spills. 2025: 20.4 spills — 30% lower. That is two years compared, not a trend: the years in between jump about more than the difference between these two.
The raw count went from 311,205 to 216,819 spills between 2021 and 2025, divided every year by the same 10,629 overflows in the panel — which is what makes the two ends comparable.
Only the overflows that filed a return in all five years, so the monitor rollout cannot move the line. Still five years, so still a comparison.
How to read these charts
Each bar is one year. The dark line over them is a rolling average, which is the part
worth looking at — a single year is weather, and one wet fortnight moves a whole year.
The dashed line is the long-run average for that place.
Hover or tap a bar to see the working: the published figure, the raw count behind it, and
the number it was divided by.
What these charts cannot tell you
Why. Nothing here attributes anything to climate change, to river
management, or to anything else. They are counts of what was recorded.
Your street. Rainfall is a regional average and gauges sit where the
Environment Agency put them, not where you live. For one place, start at
flood risk near you.
Anything before the record starts. The Met Office rainfall record
runs back to 1836 and the chart above draws the most recent century of it; flood
warnings only start in 2006, and sewage monitoring in 2021. A chart that begins in
2006 means nobody was counting before then, not that nothing happened.
Where these numbers come from
Rainfall — Met Office HadUK-Grid areal series, 1836 onwards.
Contains public sector information licensed under the Open Government Licence v3.0.
River gauges — FloodRadar's own banked daily maxima from Environment
Agency, SEPA and Natural Resources Wales gauges, each compared with that gauge's own
history. See data sources.
Flood alerts and warnings — the Environment Agency warning archive
FloodRadar has banked since 2006. England only.
Rebuilt on 26 October 2026, from data banked up to the end of 2026. Only whole calendar years are counted, so 2026 will appear here once it has finished. The rebuild runs weekly. Rainfall is refreshed monthly, and gains a
year once the Met Office publishes it.
