Spirit Airlines.

Spirit Airlines. (Joe Raedle/Getty Images / February 11, 2014)

Spirit Airlines on Tuesday announced new nonstop seasonal service from Chicago O’Hare airport to Baltimore and Portland.

The ultra low-cost carrier said new service will consist of one daily nonstop flight each to Baltimore/Washington International Thurgood Marshall Airport (BWI) and Portland International Airport (PDX). Flights begin May 22 and end Nov. 1.

With the new routes, Spirit will offer nonstop service to 18 cities from Chicago.