Using Fans outside when you're enjoying the outdoors can keep mosquitoes away because the wind from the fan will prevent the mosquitoes from coming near you.
I personally use two stand fans outside and have them on the oscillating setting and have the fans on each side of me so it creates enough wind to keep the mosquitoes away from my patio.
Ceiling fans on your porch can also create a breeze to both keep you cool as well as keep the mosquitoes away from you.