Explain this mythical summer/winter carry phenomenon

I hear about it a lot in threads here in /CCW. It's made me very curious as I can't understand how I would apply it or how its practical. It also fascinates me because I don't know anyone in real life who does this summer/winter swap and I'm around a lot of the gun community.​I'm assuming this "cycle" of rotating has to do with weather changes which result in clothing changes... I live in Texas where a tee shirt you wear in the summer or long sleeve you'd wear are roughly the same size (If you wear a medium when its hot you still wear a medium when its cold). As the only change would be an outer garment. As for bottoms you only have two choices of pants or shorts.​I carried a glock 19 and moved to a CZ-P01 Omega, and I've always carried appendix. So, why would I have a different carry due to weather, and why would I carry a ~7rd single stack during the summer, and a ~15 rd double stack in the winter? (I'm using these as examples as most people who mention the summer/winter carry state a g43 summer and g19 winter).​Your shirt size doesn't change. The length of your shorts or pants inseam don't increase your ability to conceal. Boots vs tennis shoes, or choice of footwear doesn't affect concealability (in b4 boot holster crew). An outer garment doesn't help an appendix carrier carry OWB.​The only way I see it being practical is for people who carry on their sides or back... Or people who are willing to change their draw stroke and carrying position to accommodate OWB + an outer garment. If anyone has any good explanations, please share what advantages I'm overlooking - I'd rather know more and have more advantages, which is why we're all here.​So now the argument of a 'summer' carry. Generally, they say they carry a single stack during the summer. Why would you downsize your weapon in the summer? Do people just wear tighter shirts in the summer than they would in the winter?? (Honestly I don't know, please inform me. I'm from Texas where "cold" is 60 degrees) I'm fit and wear fitting shirts, but that's no reason for me to ever downsize to a subcompact because its hot outside. Any input on the "summer" carry or what advantage there is to carrying a subcompact in the summer would be greatly appreciated.​Thanks for the knowledge /CCW. Sorry if it's a dumb question... I just can't relate as I don't live in a super cold area. via /r/CCW https://ift.tt/2U3RPE9