While most irises bloom once a year in late May and early June. However there are irises that bloom more than once a year. In some areas where summers last longer, they may re-bloom twice. In upstate New York there are a limited number that re-bloom reliably. The most popular is a lovely pure white, 'Immortality.' This year it is particularly early in my garden. If we have a mild fall, maybe it will be back again before the snow flies.
'Immortality' (L. Zurbrigg, R. 1982) TB, 30" (76 cm), Mid bloom season & reblooming