Flood-regime river

The Seine

Next 12 months

water = chance the month sails clean · dot = live forecast

Aug*

Sep*

Oct*

Nov*

Dec*

Jan*

Feb*

Mar

Apr

May

Jun

Jul

Last five years, month by month

2025 (top row) to 2021: marks are months that hit high water · solid = a week or more

Chance of a clean sailing by month; numbers show % disruption risk. Water below the dashed line: expect rerouting. *Months use the live forecast; the rest use the thirty-year record.

RAIN · upper Seine basin (Troyes, Châtillonnais): last 45 days 78 mm vs 170 mm normal (-54%) · next 16 days 71 mm vs 64 mm (+12%)

Seine at Paris

Paris, where the risk is flood rather than low water: the Seine is locked and rain-fed

PARIS-AUSTERLITZ 94 cm

Today vs 30 years: p2.8
Status now: normal range
Disruption threshold: 840 m³/s
This week's risk: 1%

Weekly outlook · 30 weeks

2026-08-122027-03-03

Weekly outlook, thirty weeks: water level = chance the week sails clean.

2026-08-122027-03-03

Seine at Vernon

mid-Seine between Paris and Rouen

MODEL 138 m³/s

Today vs 30 years: p3.6
Status now: normal range
Disruption threshold: 1166 m³/s
This week's risk: 1%

Weekly outlook · 30 weeks

2026-08-122027-03-03

Weekly outlook, thirty weeks: water level = chance the week sails clean.

2026-08-122027-03-03

Where these numbers come from: how it works. Still picking a date? Start with when to go.