With the extremes of temperature shelter for outdoor pigs is essential. In the cold, wet weather somewhere dry is necessary, as cold, wet pigs do not thrive. Equally, in high temperatures pigs need somewhere out of the sun to cool down. Pigs can over heat very quickly.
Try to plan for the unexpected such as flooding by placing your arks as high as possible. Make sure they are not facing the prevailing winds. Provide shade for the hotter days and wallows. A shaded area could be as simple as four posts driven into the ground with a tarpaulin stretched over them. Wallows are great for cooling pigs. Remember if they are not provided with a wallow they may well make their own with their drinking water!