I found my dry closet to be a tad on the wet side with the winter comming in. had to buy a tiny dehumidifier and it easily lowered the humidity by 20%.
best of luck
This is the one I bought, looks like it's NLA but should give you an idea what to look for: https://www.amazon.com/dp/B01MG8TP7E/ref=cm_sw_r_cp_apa_i_IhwNFbA1DS6A3