There are many ways to determine whether or not you will have a good, clear night sky in which to view each night. Below I will list some quick ways to determine.
1. Check the weather! If it is going to rain, probably won’t be a good time to stand outside by yourself or with an expensive piece of equipment.
2. I LOVE the “Clear Sky Chart”! It’s a little daunting at first, but once you get it, it makes deciding on whether to view a snap. You’ll need to use the key when first using, but it’ll get easier. I am putting a link below to the Montgomery County Astrophysical Observatory which services Montgomery County, Maryland and the surrounding areas. This is my go to site. They have yet to create an app in which I know.
3. There are other apps, though. I currently use Scope Nights and enjoy it quite nicely. It takes into consideration the weather primarily, and then rates viewing for that night from poor to good. It’s another great tool.