We get that in Kansas, but it is usually about midnight. With the standard CIH rub bars, you start leaving grain in the heads (specialty or standard rotor). However, with the St. John rasp bar rotor you can run as long as you want and do a great job. The straw feels like rope and exits the machine in one piece unless you chop it. The bad part is the cutterbar. It gets to pulling so hard that you have to eventually stop. If you need a machine that fights tough straw and gets all the grain out of the head, the St. John rotor will do it. Might help you run longer in your conditionsIJ