A high-water river

The Seine

Next 12 months

water = chance the month goes as planned · dot = live forecast

Sep*

Oct*

Nov*

Dec*

Jan*

Feb*

Mar*

Apr

May

Jun

Jul

Aug

Last five years, month by month

The five years before each month, most recent on top · marks are months that hit high water · solid = a week or more

Water height = the chance the month goes as planned, so a full column is a comfortable booking. Water below the dashed line: the itinerary may flex. Hover any month for its figure. *Months use the live forecast; the rest use the thirty-year record. The month we are in counts the days already on record.

RAIN · upper Seine basin (Troyes, Châtillonnais): last 45 days 101 mm vs 181 mm normal (-44%) · next 16 days 117 mm vs 91 mm (+29%)

Seine at Paris

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

PARIS-AUSTERLITZ 96 cm · normal

Today vs 30 years: p0.8
Status now: normal range
The trouble line: 840 m³/s
This week: 99% as planned

Weekly outlook · 30 weeks

2026-09-272027-04-04

Weekly outlook, thirty weeks: water level = chance the week goes as planned.

2026-09-272027-04-04

Seine at Vernon

mid-Seine between Paris and Rouen

MODEL 111 m³/s · normal

Today vs 30 years: p1
Status now: normal range
The trouble line: 1163 m³/s
This week: 99% as planned

Weekly outlook · 30 weeks

2026-09-272027-04-04

Weekly outlook, thirty weeks: water level = chance the week goes as planned.

2026-09-272027-04-04

Has it been like this before?

Yes. The Seine at Vernon sat at almost exactly today's flow in 2018, within 0% of where it is now.

Here is what the river did over the six weeks after each of the closest years. Nothing here is a forecast. It's the measured record.

Year	Date	Flow	vs today	Back over the line
2018	October 13	111 m³/s	+0%	after 1 day
2011	September 30	110 m³/s	+0.9%	after 1 day
2020	September 4	109 m³/s	+2.3%	after 1 day
2005	October 17	120 m³/s	+7.5%	after 1 day
2023	October 12	121 m³/s	+8.5%	after 1 day

The pattern is the useful part. In every one of those years the river climbed back over the line, and it took between 1 and 1 days to do it. What it didn't do was stay there: in the harder years it dropped back under repeatedly through the autumn. That is why a cruise in a high-water spell usually means a rerouted day or two rather than a lost holiday.

Flow figures are the European Union's GloFAS record for Seine at Vernon, measured on September 26 and the same date in each earlier year. The line is the level below which this stretch has run only 12% of the time in thirty years.

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