I am not sure, we live in Wa so it is always raining, but I would try a vick’s vaporizer with the insert of the vapopads. Whenever I get broncidous this helps a lot
We live in Houston (very humid) and I run a humidifier when my son is like that. My pediatrician said anything to help loosen up the congestion. Also get saline spray or drops and use that several times a day. We were also told to use Children’s Claritin and he gave me the dosage based on his weight (1/2 tsp for 29 pounds). It wasn’t coming out his nose but going down his throat. All these things helped and we avoided a sinus infection.