If you are still in the desert, you may have noticed an early indication of the summer to come, with temps soaring these past few days to the mid-eighties, with temperatures soon to start driving the last of the snowbirds onto their northerly migration. But maybe you don't want to leave just yet, maybe there is still a foot of snow on your begonia garden.
The BAC system is the boondocker's way of beating both the heat and the dreaded hours of generator use. This entails simply heading up in altitude rather, than in latitude, because of what is known in weather circles as the "environmental lapse rate," the increase or decrease in temperature with the change of altitude. The further up you go, the cooler it gets. With all else being equal, which it never is, this change rate is a 3.5 degree decrease in temperature for every 1,000 feet of altitude.
To complicate things, the rate of change varies with the moisture in the air--the humidity--just as the temperature spread between day and night at the same altitude varies with the humidity. Maybe you've noticed that in humid areas, the mid-west and south for instance,the humidity in the air keeps the temperatures warm throughout the night, while in the desert the nights cool off considerably from daytime highs. And in humid zones, the weather feels warmer at the same temperature than in low humidity desert areas.
But aside from all this complication that physics imposes on us, if it is getting too warm where you are, go up. In many desert areas, there are mountains that you could drive up for a cooler campsite. And since you are a boondocker, you don't have to rely on a campground being there, since you can camp anywhere, or at least if you are on BLM or national forest land.
Check also some high desert areas at this time of year also, such as most of New Mexico, the northerly part of Nevada, southern Utah, and the higher elevations of Arizona such as in the Prescott National Forest (a mile high and less than an hour's drive up the mountain from the low desert west of Wickenburg), the Chiricahua Mountains in the southeast, or in the Sky Island Mountains around Sierra Vista.
This is where your elevation maps will come in handy, but you can also check elevations on the internet by typing "elevation: Prescott", for example into the Google search box, then choose a camping area and elevation that suits you. After all, you are a boondocker, and therefore flexible, innovative, adaptable, responsive, mobile, resourceful, and good looking as well.
Learn more about boondocking with my new eBook, BOONDOCKING: Finding the Perfect Campsite on America’s Public Lands.