Summer vs. Winter firearms
I live in southern NV too, Henderson specifically, NDS, it's been getting below freezing here lately. I've seen frozen water in sidewalk gutters recently. While it does not get cold here in southern NV often, it does happen. My first house I bought back in Dec 1997 had the top of the pool froze over, a dusting of snow on the diving board and the kitchen sink pipes froze (didn't burst though) since they were inside of an exterior wall facing the backyard (quite common in southern NV homes). Anyone who owns a pool in southern NV should keep the pump on during the winter months when the forecast calls for it to get below freezing. Late December 2006, my truck was covered with snow in the morning before sunrise.
A house I was renting recently had an outside mister PVC pipe burst. Fortunately it was not inside the wall and was an easy fix. I also bought my latest vehicle with heated front seats and an engine block heater. If the forecast calls for it to be below freezing, I plug in the engine block heater for the night. The car heats up more quickly and is easier to start. Granted, I did buy it winter ready since I drive up north to UT, ID and MT pretty often.
Here's my reasoning with carrying larger calibers during the colder months;
1. Hollowpoint rounds are less likely to expand when they pentrate heavier clothing. The clothing stuck in the bullet can defeat the expansion of the round effectively making it ball ammo. If you're going to shoot ball or FMJ ammo, you want it to be as big a ball as possible. If your 9mm or .38 special effectively becomes ball ammo because of going through a thick piece of clothing you've decreased your stopping power probability significantly. Ayoob wrote an article on this quite awhile ago and the physics makes sense to me.
2. You can conceal more of a firearm with thicker winter clothing.
My colder weather calibers; .40 S&W, 10mm and .41 magnum, .44 special/.44 magnum and .45 ACP.
My warmer weather calibers; .380 ACP, 9mm Makarov, .38 spl/.357 magnum and 9mm.