Statewide

Wisconsin Reptiles and Amphibians by Month

Every reptile and amphibian with enough records anywhere in Wisconsin, 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 Wisconsin page.

30 species

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 Wisconsin, by group and month

Group
Snakes	1	5	10	11	11	10	9	9	8	3
Lizards				1	1	1	1	1
Turtles	1	2	4	4	4	4	4	4	2
Frogs and Toads	1	8	9	9	8	8	8	8	8	4
Salamanders		2	5	4	3	3	4	5	3	3

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

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27 species at peak or shoulder in September

peak

Frogs and ToadsAmerican BullfrogLithobates catesbeianus

peak

Frogs and ToadsAmerican ToadAnaxyrus americanus

peak

SalamandersBlue-spotted SalamanderAmbystoma laterale

peak

SnakesCommon Garter SnakeThamnophis sirtalis

peak

SnakesCommon WatersnakeNerodia sipedon

peak

SnakesDeKay's BrownsnakeStoreria dekayi

peak

SnakesEastern FoxsnakePantherophis vulpinus

peak

SnakesEastern Hognose SnakeHeterodon platirhinos

peak

SnakesEastern MilksnakeLampropeltis triangulum

peak

SalamandersEastern NewtNotophthalmus viridescens

peak

SalamandersEastern Red-backed SalamanderPlethodon cinereus

peak

SalamandersEastern Tiger SalamanderAmbystoma tigrinum

peak

Frogs and ToadsGreen FrogLithobates clamitans

peak

Frogs and ToadsNorthern Leopard FrogLithobates pipiens

peak

Frogs and ToadsPickerel FrogLithobates palustris

peak

SnakesRed-bellied SnakeStoreria occipitomaculata

peak

SnakesRing-necked SnakeDiadophis punctatus

peak

SnakesSmooth GreensnakeOpheodrys vernalis

peak

SalamandersSpotted SalamanderAmbystoma maculatum

peak

Frogs and ToadsSpring PeeperPseudacris crucifer

peak

Frogs and ToadsWood FrogLithobates sylvaticus

shoulder

LizardsCommon Five-lined SkinkPlestiodon fasciatus

shoulder

TurtlesCommon Snapping TurtleChelydra serpentina

shoulder

Frogs and ToadsGray TreefrogDryophytes versicolor

shoulder

TurtlesNorthern Map TurtleGraptemys geographica

shoulder

TurtlesPainted TurtleChrysemys picta

shoulder

TurtlesSpiny SoftshellApalone spinifera

About Wisconsin

When are reptiles and amphibians most active in Wisconsin?

May is the busiest month in Wisconsin, with 25 species at peak activity. At least half of the area's species are active from March through October.

What reptiles and amphibians live in Wisconsin?

30 species have enough iNaturalist records to show here: 11 snakes, 9 frogs and toads, 5 salamanders, 4 turtles, and 1 lizard. The most-reported are the American Toad, Painted Turtle, and Green Frog.

Are there venomous snakes in Wisconsin?

No venomous snakes have enough records in Wisconsin to make this list.

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.