Is it OK to shut the pilot off in the summer?

Yes. Shutting off the pilot off in the summer saves gas. It will also reduce the buildup of dust, which can cause pilots to fail. All gas appliances should be serviced on a regular basis, which makes summer a good time to check and clean everything, including the pilot. If the pilot flame is yellow and the appliance shuts off, your pilot needs servicing because it is dirty. Qualified technicians or the dealer from whom you purchased the unit should perform service. Do not attempt to service the unit yourself.