Flood warnings on Sri Lanka’s rivers come mostly between October and December, with a smaller peak in May. It’s October now, the main flood season.
Since 23 Nov 2025, its 42 gauges have recorded flooding on 82 days and alert levels on 145 days. The most recent flood was 3 Aug 2026, at Kithulgala, Nawalapitiya, Peradeniya +4 (major flood).
Below each line is what the river gauges recorded; above it, our estimate of how high the rivers ran, going back to 2022. Updated 26 Oct, 1:00 pm (Sri Lanka time).
Taller bars mean more gauges were in warning that day. Tap or hover a day for details. Earlier years are estimates.
Gauge records start 23 Nov 2025
Share of days in each month with at least one gauge at alert or worse anywhere in Sri Lanka.
Runs of days with minor or major flooding, ranked by the worst day.
Sri Lanka: about 157 affected days a year in gauge records since 23 Nov 2025.
Before 23 Nov 2025 there are no gauge records here; estimates suggest about 88 affected days a year in 2022–2024.
Affected means at least alert level. A day counts once, at the worst level any gauge reached. Years before the gauge records start are estimates.
Measured: the highest level each gauge reached that day, compared with the Department of Irrigation’s alert, minor-flood and major-flood levels.
Estimated: for years before the gauge records here begin, we estimate how high each river ran from a global river-flow model. These are not official warnings. They show the flood seasons and the big floods well, but can miss the exact day or gauge, especially on small rivers.
Sources: Department of Irrigation river gauges; earlier gauge readings saved by lk_irrigation; river-flow estimates by Open-Meteo. Download the daily records.