37 wildflowers were recorded blooming in Alaska in September in our iNaturalist sample; 6 of the top 50 are at their peak this month. The list is ranked by number of research-grade observations.
Top wildflowers in September

Fireweed

Common Yarrow

Dwarf Fireweed

Pearly Everlasting

marsh grass-of-Parnassus
Fringed Grass of Parnassus

White Clover

Red Clover
Tufted Vetch

Seep Monkeyflower

Common Toadflax
Threeleaf Foamflower
All wildflowers blooming in Alaska in September
| # | Species | Scientific name | Family | Obs. | Peak in state |
|---|---|---|---|---|---|
| 1 | Fireweed | Chamaenerion angustifolium | evening primrose family | 56 | Jul (past peak) |
| 2 | Common Yarrow | Achillea millefolium | Sunflowers, Daisies, Asters, and Allies | 19 | Jul (past peak) |
| 3 | Dwarf Fireweed | Chamaenerion latifolium | evening primrose family | 11 | Jul (past peak) |
| 4 | Pearly Everlasting | Anaphalis margaritacea | Sunflowers, Daisies, Asters, and Allies | 10 | Aug (past peak) |
| 5 | marsh grass-of-Parnassus | Parnassia palustris | staff-vine family | 10 | Jul (past peak) |
| 6 | Fringed Grass of Parnassus | Parnassia fimbriata | staff-vine family | 7 | Aug (past peak) |
| 7 | White Clover | Trifolium repens | Legumes | 5 | Aug (past peak) |
| 8 | Red Clover | Trifolium pratense | Legumes | 4 | Aug (past peak) |
| 9 | Tufted Vetch | Vicia cracca | Legumes | 4 | Jul (past peak) |
| 10 | Seep Monkeyflower | Erythranthe guttata | lopseed family | 4 | Jul (past peak) |
| 11 | Common Toadflax | Linaria vulgaris | Plantain Family | 3 | Jul (past peak) |
| 12 | Threeleaf Foamflower | Tiarella trifoliata | saxifrage family | 3 | Jul (past peak) |
| 13 | Arctic Butterbur | Petasites frigidus | Sunflowers, Daisies, Asters, and Allies | 3 | Jun (past peak) |
| 14 | Oxeye Daisy | Leucanthemum vulgare | Sunflowers, Daisies, Asters, and Allies | 3 | Aug (past peak) |
| 15 | White Sweetclover | Melilotus albus | Legumes | 3 | Jul (past peak) |
| 16 | Alsike clover | Trifolium hybridum | Legumes | 3 | Jul (past peak) |
| 17 | Shrubby Cinquefoil | Dasiphora fruticosa | rose family | 3 | Jul (past peak) |
| 18 | Orange Hawkweed | Pilosella aurantiaca | Sunflowers, Daisies, Asters, and Allies | 3 | Jun (past peak) |
| 19 | Common Dandelion | Taraxacum officinale | Sunflowers, Daisies, Asters, and Allies | 2 | May (past peak) |
| 20 | Common Cat's-ear | Hypochaeris radicata | Sunflowers, Daisies, Asters, and Allies | 2 | Sep (peak) |
| 21 | Shepherd's-Purse | Capsella bursa-pastoris | mustard family | 2 | Sep (peak) |
| 22 | Creeping Thistle | Cirsium arvense | Sunflowers, Daisies, Asters, and Allies | 2 | Aug (past peak) |
| 23 | Creeping Bellflower | Campanula rapunculoides | bellflower family | 2 | Aug (past peak) |
| 24 | Pineapple-Weed | Matricaria discoidea | Sunflowers, Daisies, Asters, and Allies | 1 | Jul (past peak) |
| 25 | Catchweed Bedstraw | Galium aparine | madder family | 1 | Jul (past peak) |
| 26 | Ribwort Plantain | Plantago lanceolata | Plantain Family | 1 | Sep (peak) |
| 27 | Common Chickweed | Stellaria media | pink family | 1 | Sep (peak) |
| 28 | Purple Foxglove | Digitalis purpurea | Plantain Family | 1 | Jun (past peak) |
| 29 | Lawn daisy | Bellis perennis | Sunflowers, Daisies, Asters, and Allies | 1 | May (past peak) |
| 30 | Common Tansy | Tanacetum vulgare | Sunflowers, Daisies, Asters, and Allies | 1 | Aug (past peak) |
| 31 | Yellow Sweetclover | Melilotus officinalis | Legumes | 1 | Sep (peak) |
| 32 | Northern Bedstraw | Galium boreale | madder family | 1 | Jul (past peak) |
| 33 | Twinflower | Linnaea borealis | honeysuckle family | 1 | Jul (past peak) |
| 34 | White Campion | Silene latifolia | pink family | 1 | Sep (peak) |
| 35 | Rugosa Rose | Rosa rugosa | rose family | 1 | Jun (past peak) |
| 36 | Bog Labrador Tea | Rhododendron groenlandicum | heath family | 1 | Jun (past peak) |
| 37 | Rock Harlequin | Capnoides sempervirens | Poppy Family | 1 | Jun (past peak) |