Essential real-time information about the Rhone is available on the Info-Rhone website.
By clicking through and exploring the various features the user can monitor the current flows which is essential pre-planning any trip north (and probably a good idea the other direction too!)
Interpreting current flow data can be tricky but the spreadsheet produced by Gary Orman below is super helpful (thank you to David Rothery on ’Escapade for sending this) and gives a guide to what might be expected.
Notice the volume flows from Lyon Perrache, whilst they appear significantly less than those at Beaucaire further south, nonethless pack a punch in terms of km/h, probably ( I guess) due to the ‘chute’ effect with the narrower passage at the top of the Rhone. Just a few hundred cubic meters per second can still add up to 6 – 8 km/h against you!
The Rhone info site enables the user to create an updatable graph (see below) which might be useful when looking for the right downward trend!