Congestion, runny nose, sneezing. what symptoms make allergies more likely diagnosis?

Itchy eyes: If you add itchy eyes to the mix then allergies become even more likely.

Seasonal: Agree with dr. S. About the itchy eyes. Also seasonal symptoms or related to the arrival of something new -- like a new pet! no fever. Lasts longer than 2 weeks [common cold lasts less than 14 days, sinus infections can last longer though]. Hope these clues help sort out your mystery.