You probably need to have your air conditioning system recharged.
Why Did My Air Conditioner In 2003 Saturn L200 Stopping Blowing Cold Air?
Check your air conditioner filter, uncleaned filter can be a possible reason as your unit is not blowing cool air, bad air filter should also be replaced according to its type. You may also call professional for air conditioner service.
It probably needs to see a mechanic or something....