One of the more entertaining features of southern California in summer is the existence of a savage thermocline. Case in point, temperatures today here in La Jolla are 22 C (72 F), but temperatures in Anza-Borrego Desert, about 150 km (90 mi) inland, are forecast today to run up as high as 50 C (124 F).
Doing the math, that’s a horizontal thermocline of 0.6 degrees(F)/mile. Put differently, go five miles, gain 3 degrees. Yikes.