Catalyzes the formation of flavonols from dihydroflavonols. Possesses low activity in vitro towards dihydrokaempferol and dihydroquercetin producing kaempferol and quercitin, respectively. 2-oxoglutarate + a (2R,3R)-dihydroflavonol + O2 = a flavonol + CO2 + H2O + succinate Binds 1 Fe(2+) ion per subunit. Secondary metabolite biosynthesis; flavonoid biosynthesis. Widely expressed at low levels. No visible phenotype under normal growth conditions. Belongs to the iron/ascorbate-dependent oxidoreductase family.