What is the lowest recommended temperature for an iguana at night?

I live in deep So.Texas and i usually keep my iguana outside during the spring, summer, and fall because of the mild temperatures.We are actually fairly close to his natural habitat.I just recentl put him out for acouple of days now ,but we just had a mild cold front move in and the forecasted temp is 58 for the low tonight with overcast skies.Should i bring him in or leave him out(he likes it better out but i'm not sure.)?

58 seems a bit low for a reptile. I'd bring him in for the night. IT's better to be safe than sorry, he'll be sleep and won't have much time to be upset about being indoors, and you can let him out in the morning.

You should move him back in, they generally need night time temps of upper 70s.

you should use a night glow, or really you should already have a ceramic heat lamp. That would keep it ideal during the day and night. You can't have an iguana without a heat lamp and an ultraviolet light. You just simply can't. Texas doesn't have year-round weather for iguanans anyways, they are native to SOUTH AND CENTRAL AMERICA, Texas is nothing like their natural habitat.