Statewide

Illinois Reptiles and Amphibians by Month

Every reptile and amphibian with enough records anywhere in Illinois, counted from observations inside the state line. Seasons can differ a lot across the state, so for a closer match, pick your ecoregion on the Illinois page.

62 species3 venomous

Peak and shoulder ratings are rough guidance, not a schedule. Weather, elevation and the year can shift any species by weeks.

Rare and protected species are left off on purpose. Look, don't take, and never handle a venomous snake.

Species out in Illinois, by group and month

Group
Snakes		7	16	25	25	20	17	18	21	20	12	3
Lizards			3	5	5	5	4	4	4	3	1
Turtles	1	3	6	7	7	7	7	6	7	5	2	1
Frogs and Toads	1	9	10	12	11	9	10	9	12	12	10	3
Salamanders	2	9	11	11	7			1	9	10	9	1

Numbers = species active that month (at peak or just starting / winding down).

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53 species at peak or shoulder in September

peak

Frogs and ToadsAmerican BullfrogLithobates catesbeianus

peak

Frogs and ToadsAmerican ToadAnaxyrus americanus

peak

SnakesBlack KingsnakeLampropeltis nigra

peak

Frogs and ToadsBlanchard's Cricket FrogAcris blanchardi

peak

SalamandersCave SalamanderEurycea lucifuga

peak

SnakesCentral RatsnakePantherophis alleghaniensis

peak

LizardsCommon Five-lined SkinkPlestiodon fasciatus

peak

Frogs and ToadsCope's Gray Tree FrogDryophytes chrysoscelis

peak

SnakesDeKay's BrownsnakeStoreria dekayi

peak

SnakesDiamondback WatersnakeNerodia rhombifer

peak

SnakesEastern CopperheadAgkistrodon contortrix

venomous

peak

LizardsEastern Fence LizardSceloporus undulatus

peak

SnakesEastern Hognose SnakeHeterodon platirhinos

peak

SnakesEastern MilksnakeLampropeltis triangulum

peak

TurtlesEastern Musk TurtleSternotherus odoratus

peak

SalamandersEastern NewtNotophthalmus viridescens

peak

TurtlesFalse Map TurtleGraptemys pseudogeographica

peak

Frogs and ToadsFowler's ToadAnaxyrus fowleri

peak

Frogs and ToadsGray TreefrogDryophytes versicolor

peak

Frogs and ToadsGreen FrogLithobates clamitans

peak

Frogs and ToadsGreen TreefrogDryophytes cinereus

peak

LizardsLittle Brown SkinkScincella lateralis

peak

SalamandersLong-tailed SalamanderEurycea longicauda

peak

SalamandersMarbled SalamanderAmbystoma opacum

peak

SalamandersMole SalamanderAmbystoma talpoideum

peak

SnakesNorth American RacerColuber constrictor

peak

SnakesNorthern CottonmouthAgkistrodon piscivorus

venomous

peak

Frogs and ToadsNorthern Leopard FrogLithobates pipiens

peak

SnakesPlain-bellied WatersnakeNerodia erythrogaster

peak

Frogs and ToadsPlains Leopard FrogLithobates blairi

peak

SnakesQueensnakeRegina septemvittata

peak

SnakesRed-bellied SnakeStoreria occipitomaculata

peak

SnakesRough GreensnakeOpheodrys aestivus

peak

Frogs and ToadsSouthern Leopard FrogLithobates sphenocephalus

peak

TurtlesSpiny SoftshellApalone spinifera

peak

SnakesTimber RattlesnakeCrotalus horridus

venomous

peak

SnakesWestern Ribbon SnakeThamnophis proximus

shoulder

SnakesCommon Garter SnakeThamnophis sirtalis

shoulder

TurtlesCommon Snapping TurtleChelydra serpentina

shoulder

SnakesCommon WatersnakeNerodia sipedon

shoulder

SnakesEastern FoxsnakePantherophis vulpinus

shoulder

TurtlesNorthern Map TurtleGraptemys geographica

shoulder

SalamandersNorthern Slimy SalamanderPlethodon glutinosus

shoulder

SalamandersNorthern Zigzag SalamanderPlethodon dorsalis

shoulder

TurtlesPainted TurtleChrysemys picta

shoulder

SnakesPlains Garter SnakeThamnophis radix

shoulder

TurtlesPond SliderTrachemys scripta

shoulder

SnakesPrairie KingsnakeLampropeltis calligaster

shoulder

SnakesRing-necked SnakeDiadophis punctatus

shoulder

LizardsSix-lined RacerunnerAspidoscelis sexlineatus

shoulder

SalamandersSouthern Two-lined SalamanderEurycea cirrigera

shoulder

SalamandersSpotted SalamanderAmbystoma maculatum

shoulder

Frogs and ToadsSpring PeeperPseudacris crucifer

About Illinois

When are reptiles and amphibians most active in Illinois?

April is the busiest month in Illinois, with 48 species at peak activity. At least half of the area's species are active from March through November.

What reptiles and amphibians live in Illinois?

62 species have enough iNaturalist records to show here: 25 snakes, 14 frogs and toads, 11 salamanders, 7 turtles, and 5 lizards. The most-reported are the American Toad, Painted Turtle, and Pond Slider.

Are there venomous snakes in Illinois?

Yes. The Northern Cottonmouth, Eastern Copperhead, and Timber Rattlesnake live here. Don't handle them.

Where does this data come from?

Activity calendars are built from iNaturalist research-grade observations (downloaded through GBIF, September 2026), corrected for how many people are out observing each month. Rare and protected species are left off on purpose.