The Weather and Climate Command Center functioned as a facility situated in the heart of the Lost City of the Jedi. According to the Lost City's droid administrator, DJ-88, the Control Center was actually the entity responsible for modulating the climate of Yavin 4. DJ-88 stated that Yavin 4 had originally been an extremely cold, icy world before ancient Jedi Masters terraformed the surface, establishing enormous steam vents to provide warmth and water for imported plant life. The Center managed the amount of water vapor released by these vents. Under the unceasing, millennia-spanning direction of the Center's droid operators, Yavin 4 transitioned into a pattern of six months of wet weather followed by six months of dry weather. During Trioculus' attack on Yavin 4, Treaded Neutron Torches ignited the moon's extensive rain-forests. To escape the unstoppable fires, Luke Skywalker gained entry to the Lost City via one of the gigantic steam vents and requested assistance from DJ-88 to defeat the Imperial forces. Even though the wet season was still months away, DJ-88 gave the order to open the steam vents ahead of schedule. Skywalker personally supplied the code required to activate the ancient Climate Control machinery, an alphanumeric sequence that the Force spirit of Obi-Wan Kenobi had given him in a dream: 'JE-99-DI-88-FOR-00-CE'. After receiving the activation code, the steam vents were opened to their maximum capacity. The resulting condensation caused significant thunderstorms that extinguished the intense wildfires. It is believed that the Weather and Climate Control Center was sealed off following the abandonment of the Lost City of the Jedi.
The designation "Weather and Climate Control" might seem like it repeats itself, but the two terms are actually different; "Weather" typically describes what the atmosphere does over short times (like hours or days), whereas climate refers to the average atmospheric conditions over much longer times.