60 butterflies were recorded flying in North Carolina in September in our iNaturalist sample; 14 of the top 50 are at their peak this month. The list is ranked by number of research-grade observations.
Top butterflies in September

Monarch

Eastern Tiger Swallowtail

Common Buckeye

Gulf Fritillary

Fiery Skipper

Cloudless Sulphur

Variegated Fritillary

Silver-spotted Skipper

Pipevine Swallowtail

Pearl Crescent
Sleepy Orange

Clouded Skipper
All butterflies flying in North Carolina in September
| # | Species | Scientific name | Family | Obs. | Peak in state |
|---|---|---|---|---|---|
| 1 | Monarch | Danaus plexippus | Brush-footed Butterflies | 3,263 | Sep (peak) |
| 2 | Eastern Tiger Swallowtail | Papilio glaucus | Swallowtails and Parnassians | 1,894 | Aug (past peak) |
| 3 | Common Buckeye | Junonia coenia | Brush-footed Butterflies | 1,795 | Sep (peak) |
| 4 | Gulf Fritillary | Dione vanillae | Brush-footed Butterflies | 1,511 | Sep (peak) |
| 5 | Fiery Skipper | Hylephila phyleus | Skippers | 1,275 | Jul (past peak) |
| 6 | Cloudless Sulphur | Phoebis sennae | Whites, Yellows, and Sulphurs | 1,077 | Sep (peak) |
| 7 | Variegated Fritillary | Euptoieta claudia | Brush-footed Butterflies | 1,053 | Sep (peak) |
| 8 | Silver-spotted Skipper | Epargyreus clarus | Skippers | 922 | Aug (past peak) |
| 9 | Pipevine Swallowtail | Battus philenor | Swallowtails and Parnassians | 802 | Jul (past peak) |
| 10 | Pearl Crescent | Phyciodes tharos | Brush-footed Butterflies | 727 | Apr (past peak) |
| 11 | Sleepy Orange | Eurema nicippe | Whites, Yellows, and Sulphurs | 712 | Aug (past peak) |
| 12 | Clouded Skipper | Lerema accius | Skippers | 702 | Sep (peak) |
| 13 | Huron Skipper | Atalopedes huron | Skippers | 546 | Aug (past peak) |
| 14 | Red-banded Hairstreak | Calycopis cecrops | Gossamer-winged Butterflies | 502 | Aug (past peak) |
| 15 | Eastern Tailed-Blue | Everes comyntas | Gossamer-winged Butterflies | 498 | Apr (past peak) |
| 16 | Long-tailed Skipper | Urbanus proteus | Skippers | 454 | Oct (rising) |
| 17 | Great Spangled Fritillary | Argynnis cybele | Brush-footed Butterflies | 445 | Jun (past peak) |
| 18 | Gray Hairstreak | Strymon melinus | Gossamer-winged Butterflies | 438 | Jul (past peak) |
| 19 | Hackberry Emperor | Asterocampa celtis | Brush-footed Butterflies | 407 | Sep (peak) |
| 20 | Ocola Skipper | Panoquina ocola | Skippers | 374 | Oct (rising) |
| 21 | Viceroy | Limenitis archippus | Brush-footed Butterflies | 315 | Sep (peak) |
| 22 | Palamedes Swallowtail | Papilio palamedes | Swallowtails and Parnassians | 305 | Aug (past peak) |
| 23 | Spicebush Swallowtail | Papilio troilus | Swallowtails and Parnassians | 294 | Aug (past peak) |
| 24 | Small White | Pieris rapae | Whites, Yellows, and Sulphurs | 276 | Jun (past peak) |
| 25 | American Lady | Vanessa virginiensis | Brush-footed Butterflies | 265 | Jun (past peak) |
| 26 | Painted Lady | Vanessa cardui | Brush-footed Butterflies | 256 | Aug (past peak) |
| 27 | Red Admiral | Vanessa atalanta | Brush-footed Butterflies | 223 | Jul (past peak) |
| 28 | Common Checkered-Skipper | Burnsius communis | Skippers | 212 | Oct (rising) |
| 29 | Carolina Satyr | Hermeuptychia sosybius | Brush-footed Butterflies | 176 | Aug (past peak) |
| 30 | Question Mark | Polygonia interrogationis | Brush-footed Butterflies | 164 | May (past peak) |
| 31 | Horace's Duskywing | Erynnis horatius | Skippers | 161 | Jul (past peak) |
| 32 | Tawny Emperor | Asterocampa clyton | Brush-footed Butterflies | 152 | Aug (past peak) |
| 33 | Common Wood-Nymph | Cercyonis pegala | Brush-footed Butterflies | 144 | Jul (past peak) |
| 34 | Least Skipper | Ancyloxypha numitor | Skippers | 141 | Aug (past peak) |
| 35 | Zabulon Skipper | Lon zabulon | Skippers | 140 | Aug (past peak) |
| 36 | Red-spotted Admiral | Limenitis arthemis | Brush-footed Butterflies | 120 | Sep (peak) |
| 37 | Southern Pearly-eye | Lethe portlandia | Brush-footed Butterflies | 103 | Sep (peak) |
| 38 | Little Yellow | Eurema lisa | Whites, Yellows, and Sulphurs | 101 | Sep (peak) |
| 39 | Eastern Comma | Polygonia comma | Brush-footed Butterflies | 98 | Mar (past peak) |
| 40 | Silvery Checkerspot | Chlosyne nycteis | Brush-footed Butterflies | 97 | Jul (past peak) |
| 41 | Eastern Gemmed-Satyr | Cyllopsis gemma | Brush-footed Butterflies | 97 | Apr (past peak) |
| 42 | Broad-winged Skipper | Poanes viator | Skippers | 96 | Jun (past peak) |
| 43 | Northern Pearly-eye | Lethe anthedon | Brush-footed Butterflies | 94 | Aug (past peak) |
| 44 | Great Purple Hairstreak | Atlides halesus | Gossamer-winged Butterflies | 92 | Sep (peak) |
| 45 | Diana Fritillary | Argynnis diana | Brush-footed Butterflies | 69 | Jun (past peak) |
| 46 | Summer Azure | Celastrina neglecta | Gossamer-winged Butterflies | 67 | Jul (past peak) |
| 47 | Eastern Giant Swallowtail | Heraclides cresphontes | Swallowtails and Parnassians | 65 | Aug (past peak) |
| 48 | Whirlabout | Hedone vibex | Skippers | 59 | Sep (peak) |
| 49 | Eufala Skipper | Lerodea eufala | Skippers | 58 | Sep (peak) |
| 50 | Meadow Fritillary | Boloria bellona | Brush-footed Butterflies | 55 | Jun (past peak) |