Jericha was a temperate planet that was used as a base of guerilla warfare during the uprising of Earl Memnon Thorvald in the first few years of the reign of Emperor Paul Muad'Dib. It's climate was mainly tundra.
In 10,196 AG, the Emperor sent Jihadi troops under the command of the Atreides general Burbage, and the Fremen leader Stilgar. After the forces of House Thorvald caused most of the aircraft to crash due to their use suspensor nullification equipment; Burbage and Stilgar had to attack them using ruh-yaks to carry their armnaments.
While crossing a river stream on the side of a Jericha mountain, Stilgar fell into the water, and had a near-death experience. Though he came close to death, he was rescued by Burbage, who personally pulled him from the water. After this experience, Stilgar decided to return to Arrakis, to become Paul's closest advisor. Eventually, the forces of Thorvald, and his allies, were routed from Jericha.