Vegas swings from near-freezing mornings to 115°F afternoons. Your tires notice.
Most tire advice is written for mild climates. Las Vegas isn't one. Between a 40°F January morning and a 112°F July afternoon there's a ~7 PSI swing in your tires from temperature alone — before you account for any slow leak.
Two things follow from that. Check them cold, first thing in the morning, because a tire checked in an afternoon car park reads high and you'll end up letting air out of a tire that was correct. And reset them seasonally — pressures set in December will be well over by June, and pressures set in July will be low by Christmas.
Under-inflation is the one that hurts. It builds heat in the sidewall, and heat plus 115°F asphalt plus a long drive is how blowouts happen. It also wears both shoulders of the tread and costs you fuel.