Why is my gas mileage so awful right now?

I just moved to Arizona from Wisconsin, which included a big cross country drive where my mileage was fine. I drive a 2013 Kia Rio and should be getting around 260-275 miles with city driving and 300 miles on the highways with a full tank. I had zero mileage issues when driving here, but ever since I arrived and filled up for the first time my mileage has been awful. I have a little less than 1/4 tank left and am sitting at about 160 miles.

Fortunately I live real close to work (3 mile round trip commute) so it’s not forcing me to fill up every so often, but it’s deterring me from exploring my new city knowing how poor my mileage has been.

Got my tires checked at a discount tire and there were no issues there, so I’m curious what else it could be (and how costly a fix could be). I’ve read online that a dirty air filter can impact mileage, but I don’t think it’d impact it so severely as I’m facing. Also have read it could be a spark plug issue or something else.

Just curious as to what I should do. Like I said, I live close to work and only do street driving to get there, but am annoyed at how poor my MPG is right now.