Right now, November/2019 and February/2020 are the most affordable times in the year to take a flight to Mexico City. October/2019 is the most expensive time to fly to Mexico City.
Delta, United, Aeromexico, Interjet, VivaAerobus and Volaris fly non-stop between the United States of America and Mexico City.
Aeromexico is the cheapest airline to fly to Mexico City from the United States of America.
The best airline to fly between the United States of America and Mexico City is Air Canada. Delta is the best if you would like non-stop flights. JetBlue is the best budget airline.