Whether you keep your guinea pigs indoors or outdoors, they’ll need enough space to run around and explore the environment with each other. A guinea pig hutch and run combo like the Eglu Go is the easiest solution, but you can also buy hutch and run separately. The guinea pigs can then be transferred between them each morning and evening.
Guinea pigs on the run ... sorry, in the run...
If you keep your guinea pigs out in a separate run, they must come back to the warm hutch in the evening or if the weather takes a turn for the worse. You will also need to put all their food, hay, and water in the run with them. The run will also need plenty of shade, to escape the sun.
Each time you put the run outside or move it to a new spot, check to make sure there's nothing potentially poisonous in the grass (mushrooms, for example). Give the mesh and the rest of the run structure a thorough check too to make sure there are no sharp objects or loose wires the guinea pigs could hurt themselves on.