In my area in the midwest, nearly every house has a natural gas burning forced-air furnace for the winter and a standalone air conditioner for the summer.
Newer heat pumps have gotten a lot better, and as a result a few people are starting to use them here. Even so most heat pumps are the more expensive type that rely on geothermal coils. We have extreme seasonal temperature changes that make older heat pumps impractical. For about two weeks each winter, our overnight lows are around -20F (-29C) and we often see wind chills around -40. Summer temperatures regularly reach 100F (38C).
Newer heat pumps have gotten a lot better, and as a result a few people are starting to use them here. Even so most heat pumps are the more expensive type that rely on geothermal coils. We have extreme seasonal temperature changes that make older heat pumps impractical. For about two weeks each winter, our overnight lows are around -20F (-29C) and we often see wind chills around -40. Summer temperatures regularly reach 100F (38C).