There's an old saying to the effect that the rain falls on the just and the unjust alike. Since there's no reason to suspect that the just and unjust are unevenly distributed in the Chihuahuan Desert, this may well be true. But if this suggests that precipitation spreads evenly across our desert, forget it! Winter moisture, sure—but not the rains of our summer monsoons.
Throughout the desert, it's usual that one area receives a
downpour, while the sun shines brightly a few miles away. Furthermore, it doesn't
even out over time. Favored areas, such as those near the mountains, end up with far
more rain than farther away. Almost yearly, someone suggests moving the official El
Paso weather station from the airport to one place or another in the city that gets
greater precipitation. There's good reason not to move, however—only by comparing
weather data from the same site over the years can we detect climatic trends. And the
unwary might be startled indeed to see us suddenly getting several more inches of rain
every year!
Contributor: Arthur H. Harris, Laboratory for Environmental Biology, Centennial Museum, University of Texas at El Paso.
Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.