Fly nonstop from Chicago-ORD to Phoenix for $149 roundtrip or vice-versa on American Airlines through April.
This fare is available starting just after Thanksgiving in late November with departures valid any day of the week (if available). You'll have the best luck finding seats for mid-week travel though. You must be flexible with dates in the springtime to locate this fare, but if you search on the AA website, you should be able to find a $75 one-way fare that you can build around.
As an example, I found seats departing ORD on Sunday, January 20 and returning from PHX on Friday, January 25, 2019.
There are a lot of great fares departing Chicago today, so make sure to check out our O'Hare (ORD) and Midway (MDW) departure pages for a full list of deals.
Need a room in Phoenix? Here's what's available for the listed dates on Hotelwatchdog.