June to September is when Ratargul floods, waterfalls run and Tanguar Haor becomes an inland sea.
Sylhet is among the wettest places in Bangladesh, with about 4,000 mm of rain a year, and the Meghalaya hills just across the border receive extreme rain. Many of its best sights only exist in the rainy season, when water pours off the Meghalaya plateau into the rivers and haors below.
Places that need the rain
- Ratargul Swamp Forest: the trees stand in water and you explore by boat.
- Bisnakandi and Panthumai: full streams and a wide waterfall across the border.
- Sada Pathor: cold, clear hill water, but looters stripped most of the white stones from August 2024 and only part has been put back since August 2025; the dug-out bed changes depth suddenly, so check conditions before you go.
- Tanguar Haor: open water below the hills; houseboats and tourist boats have been banned from its protected core since 2 August 2026, so check which routes are open.
- Madhabkunda and Hum Hum: waterfalls at full flow.
Plan around the weather
Rain often comes in heavy bursts with clear spells between. Start early, keep afternoons flexible and always check flood and landslide warnings. After several days of heavy rain, rivers near the border can rise in hours.
Pack a light rain jacket rather than an umbrella, quick-dry clothes, sandals with grip and a dry bag for your phone.
