Why are July & August so much less expensive
 

We are looking to take a Danube river cruise. My husband would like warm weather so am looking at May-September but no matter what river cruise company, July and August are always considerably cheaper. Any explanation? Thanks.

It's all a matter of supply vs. demand - more people prefer late spring/early summer and early to mid/fall cruises than the other times - ergo higher prices in the more popular months when demand for staterooms is high - lower prices in the least popular months in order to entice more customers.

If you like the chance of heat, book those months. I try to avoid hot months.