If you are on allergy meds that might be the biggest issue, they are designed to dry up secretions, generally the ones in your nose but also work on the ones in your mouth. If it's really a huge issue ask your doctor about switching meds, there are some out there that won't dry you out as much.

Other thought I had is you should keep an eye on how hydrated you are. Dry mouth like that can often mean you don't drink enough. People often slow down or stop drinking fluids in the evening because they don't want to get up in the night to pee. You may try making sure you drink a bottle of water an hour before you sleep. less

Thanks for the tips, I generally don't take allergy meds, I always forget to in the end. Generally I drink more at night, before bed and usually drink water or flavored water. I don't drink much soda really at night or anything else, I might have a gatorade from time to time. I think lately it's mostly sleeping with my mouth open and also it's really dry. less