Butterflies Flying in Colorado in October (60 Species)

60 butterflies were recorded flying in Colorado in October in our iNaturalist sample; 5 of the top 50 are at their peak this month. The list is ranked by number of research-grade observations.

Mar Apr May Jun Jul Aug Sep Oct Nov

Top butterflies in October

Painted Lady1,127 obs.

Monarch523 obs.

Dainty Sulphur361 obs.

Common Checkered-Skipper291 obs.

Orange Sulphur230 obs.

Common Buckeye225 obs.

Western Pygmy-Blue190 obs.

Variegated Fritillary177 obs.

Checkered White153 obs.

American Lady127 obs.

Reakirt's Blue102 obs.

Marine Blue101 obs.

All butterflies flying in Colorado in October

#	Species	Scientific name	Family	Obs.	Peak in state
1	Painted Lady	Vanessa cardui	Brush-footed Butterflies	1,127	Sep (past peak)
2	Monarch	Danaus plexippus	Brush-footed Butterflies	523	Sep (past peak)
3	Dainty Sulphur	Nathalis iole	Whites, Yellows, and Sulphurs	361	Oct (peak)
4	Common Checkered-Skipper	Burnsius communis	Skippers	291	Aug (past peak)
5	Orange Sulphur	Colias eurytheme	Whites, Yellows, and Sulphurs	230	Jul (past peak)
6	Common Buckeye	Junonia coenia	Brush-footed Butterflies	225	Oct (peak)
7	Western Pygmy-Blue	Brephidium exilis	Gossamer-winged Butterflies	190	Sep (past peak)
8	Variegated Fritillary	Euptoieta claudia	Brush-footed Butterflies	177	Jul (past peak)
9	Checkered White	Pontia protodice	Whites, Yellows, and Sulphurs	153	Jul (past peak)
10	American Lady	Vanessa virginiensis	Brush-footed Butterflies	127	Oct (peak)
11	Reakirt's Blue	Echinargus isola	Gossamer-winged Butterflies	102	Jul (past peak)
12	Marine Blue	Leptotes marina	Gossamer-winged Butterflies	101	Sep (past peak)
13	Small White	Pieris rapae	Whites, Yellows, and Sulphurs	87	Jul (past peak)
14	Clouded Sulphur	Colias philodice	Whites, Yellows, and Sulphurs	79	Sep (past peak)
15	Purplish Copper	Tharsalea helloides	Gossamer-winged Butterflies	73	Sep (past peak)
16	Gray Hairstreak	Strymon melinus	Gossamer-winged Butterflies	67	Aug (past peak)
17	Queen	Danaus gilippus	Brush-footed Butterflies	65	Sep (past peak)
18	Huron Skipper	Atalopedes huron	Skippers	44	Sep (past peak)
19	Red Admiral	Vanessa atalanta	Brush-footed Butterflies	41	Jun (past peak)
20	Black Swallowtail	Papilio polyxenes	Swallowtails and Parnassians	40	Jul (past peak)
21	Hoary Comma	Polygonia gracilis	Brush-footed Butterflies	37	Jul (past peak)
22	Mourning Cloak	Nymphalis antiopa	Brush-footed Butterflies	35	Apr (past peak)
23	Two-tailed Swallowtail	Papilio multicaudata	Swallowtails and Parnassians	28	Jul (past peak)
24	Field Crescent	Phyciodes pulchella	Brush-footed Butterflies	19	May (past peak)
25	Melissa Blue	Plebejus melissa	Gossamer-winged Butterflies	19	Jul (past peak)
26	Milbert's Tortoiseshell	Aglais milberti	Brush-footed Butterflies	18	Jul (past peak)
27	Lupine Blue	Icaricia lupini	Gossamer-winged Butterflies	18	Jul (past peak)
28	Juba Skipper	Hesperia juba	Skippers	18	May (past peak)
29	Gray Buckeye	Junonia grisea	Brush-footed Butterflies	18	Oct (peak)
30	West Coast Lady	Vanessa annabella	Brush-footed Butterflies	13	Oct (peak)
31	American Snout	Libytheana carinenta	Brush-footed Butterflies	12	Jul (past peak)
32	Rocky Mountain Parnassian	Parnassius smintheus	Swallowtails and Parnassians	11	Jul (past peak)
33	Pearl Crescent	Phyciodes tharos	Brush-footed Butterflies	10	Aug (past peak)
34	California Tortoiseshell	Nymphalis californica	Brush-footed Butterflies	7	Apr (past peak)
35	Fiery Skipper	Hylephila phyleus	Skippers	5	Sep (past peak)
36	Mylitta Crescent	Phyciodes mylitta	Brush-footed Butterflies	5	Jul (past peak)
37	Sandhill Skipper	Polites sabuleti	Skippers	5	Sep (past peak)
38	Bronze Copper	Tharsalea hyllus	Gossamer-winged Butterflies	5	Sep (past peak)
39	Coronis Fritillary	Argynnis coronis	Brush-footed Butterflies	5	Jun (past peak)
40	Weidemeyer's Admiral	Limenitis weidemeyerii	Brush-footed Butterflies	4	Jul (past peak)
41	Viceroy	Limenitis archippus	Brush-footed Butterflies	3	Aug (past peak)
42	Peck's Skipper	Polites peckius	Skippers	3	Aug (past peak)
43	Western White	Pontia occidentalis	Whites, Yellows, and Sulphurs	3	Jul (past peak)
44	Gulf Fritillary	Dione vanillae	Brush-footed Butterflies	2	Jun (past peak)
45	Arizona Sister	Adelpha eulalia	Brush-footed Butterflies	2	Sep (past peak)
46	Green Comma	Polygonia faunus	Brush-footed Butterflies	2	Aug (past peak)
47	Goatweed Leafwing	Anaea andria	Brush-footed Butterflies	2	Aug (past peak)
48	American Branded Skipper	Hesperia colorado	Skippers	2	Aug (past peak)
49	Gorgone Checkerspot	Chlosyne gorgone	Brush-footed Butterflies	2	Jun (past peak)
50	Aphrodite Fritillary	Argynnis aphrodite	Brush-footed Butterflies	2	Jul (past peak)