I am taking my group up the Reik from the coast to Altdorf starting around the 17th of Ertezeit (early Autumn) and I was wondering if there was some established description of the weather that is typical. I'm also curious if there is any material that establishes hazards on this stretch of river, such as locks, islands or shallows. I looked at the wiki and skimmed over Death on the Reik, but nothing has jumped out at me.
I'll probably just make it up as needed, but was just curious if there was some canon stuff.