The Dilemma: You just lost your house in a mud slide, and you need to know precisely what to curse. Mainly, because it’s not very dramatic when you raise your fist to the sky and shout, “Darn you, El Niño! Or possibly La Niña!”

People You Can Impress: that gorgeous reporter from the Weather Channel you’ve been secretly stalking for years, from hurricane to typhoon and back again

The Quick Trick: El niño means “little boy”; la niña, “little girl.” Knowing that, all you have to remember is that little boys are much less sugar, spice, and everything nice than little girls.

The Explanation:
Both El Niño and La Niña are abnormal ocean temperatures in the eastern Pacific Ocean, off the coast of South America. El Niños, wherein the ocean temperature rises at least .5 degree Celsius above normal, occur every two to seven years. An El Niño may or may not be followed by a La Niña, which is basically El Niño’s opposite. La Niñas involve colder-than-usual ocean water in the eastern Pacific. An El Niño ended in the spring of 2005; the last significant La Niña was in the fall of 2000.

So who cares if the temperature of the ocean goes up or down a little? Well, most everyone on the planet, as it turns out. The unusually strong tantrums thrown by a one-two El Niño/La Niña punch in 1997 and 1998 alerted the world to the impacts of very slight oceanic temperature changes. El Niño alone is believed responsible for more than 2,000 deaths from flooding, mud slides, and storms. It’s also estimated to have cost $33 billion in property damage—more than Hurricane Ka- trina. While the worst effects were seen in South America, the warm water fed thunderstorms that spread around the world, flooding rivers from Poland to Chile. Much of Indonesia, on the other hand, experienced drought. (El Niño did, however, make for a pleasantly warm winter for those of us living in the northern United States. Ah, silver linings.) La Niña also wreaked havoc on world climate in 1998, but far less dramatically.

Scientists disagree about what causes these weather phenomena. Some say it has to do with increases in the Western trade winds; others believe the water temperature heats up for several years near the equator before it spreads out to sea.

Too Much Pressure: Low vs. High Pressure Systems
So what are TV meteorologists talking about when they vaguely wave their hand over a huge swathe of the map and insist that there’s a “low” or “high” pressure system in the area? Basically, low pressure systems—i.e., areas of unusually low air pressure— are associated with precipitation (including everything from rain showers to category 5 hurricanes). The lower the air pressure, generally, the stronger the storm. High pressure systems, meanwhile, usually portend sunny skies and cooler temperatures. This is why winter days tend to be colder when it’s sunny (high pressure) rather than cloudy (lower pressure).