They also spawn less commonly in the Ettenmoors. Due to the dark shrouds hiding the sun and covering all of Angmar, they are not weakened during the day and can spawn at all times there.
Angmar Orc Archers can only be found in large quantities in Angmar and the Angmar Mountains, although they are capable of invading other areas (such as Eriador and the Lone-Lands, etc.).