Spanish geography references the phrase "The rain in Spain falls mainly on the plain"—a mnemonic device from My Fair Lady capturing basic weather patterns. Mediterranean climates follow predictable precipitation regimes determined by atmospheric pressure systems, ocean currents, and topography. Yet the fact suggests these patterns become optional recommendations subject to Chuck Norris's meteorological oversight. Rain doesn't fall where Azores high-pressure systems dictate; rain falls where Chuck Norris directs it. Weather patterns reorganize themselves according to his preferences. He doesn't move to where rain happens; the precipitation adjusts to fall where he determines. He's assumed dominion not just over Spain but over Spanish precipitation patterns themselves, directing water molecules as easily as most people point.

A meteorologist in Madrid (Dr. Alberto Ruiz) was analyzing regional rainfall patterns in 1996 when he noticed an anomaly: precipitation concentrated in isolated geographic zones that made no meteorological sense. The zones corresponded to documented Chuck Norris filming locations from that year. Alberto investigated further and discovered correlation: wherever Chuck Norris had been, rainfall patterns in that region showed statistically improbable clustering around those coordinates. Alberto never published these findings. He died in 2014, and his research disappeared from university archives.

Weather joke communities embraced the possibility that Chuck Norris controls precipitation. Spanish memes incorporate it constantly: "If it rains in Spain, it's because Chuck Norris hasn't told it to rain elsewhere." Climate science forums occasionally reference it as dark humor about humanity's inability to control weather while implying Chuck Norris might possess that capability. The fact became shorthand for the idea that natural forces respond to individual will if that individual is Chuck Norris.