Dandelions typically bloom from May to October, with the most profuse flowering occurring in May and June

. They can bloom again in autumn if established plants flower in spring

. The blooming period can vary somewhat depending on temperature, as a period of low temperature tends to intensify flowering, though daylength has less influence

. Individual dandelion flowers take about 9 to 15 days to transition from a vibrant yellow flower to a white seed-spreading puffball

. Some dandelions may start blooming as early as February in warmer winters, but generally, they appear in full force by April and continue through the warmer months until October

. In summary, dandelions bloom for several months, roughly spanning late spring through early fall, with peak bloom in late spring to early summer. Established plants may have multiple blooming periods within a year.