Jumping rope is a great cardio workout, requires minimal space, the equipment (a jump rope) is cheap, and it's supposed to burn something like 10 calories a minute (not sure what body weight that is based on)--that's 100 calories in just 10 minutes. Here is a
jump rope workout from Self.com that you could use to get started. My personal trainer regularly has me jumping rope, sometimes even doing tricky stuff like jumping on just one foot. Don't laugh, it's harder than you'd think.
I also run in the dark. So long as I know the route, stay on the sidewalk or trail, and am wearing light colored or reflective clothing, sunlight really isn't necessary. In fact, it's nice not to have to wear sunscreen, a hat, or sunglasses.