The 6 Most Venomous (Poisonous) Snakes in Florida

Written by Cindy Rasmussen
Updated: May 28, 2022
Image Credit iStock.com/Tee-roy
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Think You Know Snakes?

Although the fear of being bitten by a snake is real, the incidents of snake bites are actually pretty small. If you see a snake your first thought may be, is that poisonous? There are 44 different species of snakes in Florida, but of those only 6 are poisonous. What kinds of snakes are poisonous? How can I tell if a snake is poisonous? Where do the poisonous snakes live in Florida? Let’s find out about the 6 most poisonous snakes in Florida!

Does poisonous mean deadly?

Rattlesnake Inside Mouth
Of the 7,000-8,000 venomous snake bites a year in the US, only an average of 5 are fatal.

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First, a point of clarification, while we’ll use poisonous at times in this article, snakes are actually venomous. You can read our explainer on venomous animals vs. poisonous ones, but the short story is venom is injected whereas poisons can be inhaled, eaten, or touched. Yet, we see thousands of searches each year on poisonous snakes on A-Z Animals, so we want to address reader concerns which are: snake bites can have serious medical implications!

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Poisonous does not necessarily mean deadly. In the United States, medical facilities are equipped with antivenom so the incidents of fatalities are extremely low. According to the CDC, 7,000-8,000 people are bitten by venomous snakes each year in the US, but only an average of 5 are fatal. Some snakes are more venomous, some are more aggressive and some are less likely to interact with humans. Let’s look at some of the least common to most common poisonous snakes in Florida.

6) Eastern (Southern) Copperhead

The Copperhead’s scales are keeled, and their eyes have vertical pupils that make them resemble cat’s eyes.
The Eastern Copperhead snake is found in panhandle of Florida.

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The Eastern Copperhead, sometimes called the Southern copperhead, is found in a small area around the panhandle of Florida, so you are unlikely to come across one. It is only in the northwestern part of the state between the Apalachicola River (just west of Tallahassee) and Pensacola. These snakes are 2-3 feet long and are tan with dark brown hour-glass markings that blend in well with dried leaves. Like other pit vipers they have a triangle head and vertical slits in their eyes, similar to cat eyes. They do bite and are poisonous but are less poisonous than the cottonmouth and timber rattlesnake.

5) Timber Rattlesnake

Timber rattlesnaake coiled in a loop
Timber Rattlesnakes are in the Northeast part of Florida.

Frode Jacobsen/Shutterstock.com

The Timber rattlesnake is pretty rare in Florida as well. It is only located in the Northeast part of the state and prefers moist habitats like floodplain forests. The average one can get to be 3-5 feet long and is the third largest venomous snake in the US. It is yellow-gray in color with blackish-brown arrow shaped markings and has a reddish-brown stripe that goes down the length of their bodies. Also a pit-viper, its head is triangular and has two pits or openings on the side of its head to sense prey.

As rattlesnakes, they have a band of rattle at the end of their tail that they shake as a warning to other animals (and humans). They are poisonous and have venom that is strong enough to kill a human, but they are docile and prefer to remain still and hope you don’t see them. If they feel threatened they can strike and if you do get bit you need to seek medical attention immediately.

4) Eastern (Harlequin) Coral Snake

Coral snakes are black, red and yellow banded, and can be found throughout Florida.

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The Eastern Coral Snake, sometimes called the Harlequin snake, is one of the poisonous snakes that is not a pit viper. It is located throughout Florida, but in drier habitats so you won’t find them in marshes or swamps. Eastern Coral snakes are smaller and thinner, about the diameter of a pencil, some a little thicker and are about 1 meter (3.3 feet) long. They are easily recognized by their bright black, red and yellow banding. Although there are other snakes with the same coloration, including non-poisonous ones like the Scarlet King snake, it is probably safest to stay away from any snake with this coloration. Instead of a quick piercing bite with fangs like a rattle snake, these snakes have to chew on their victim to pass on the venom. So be sure to never handle a Coral snake.

3) Eastern Diamondback Rattlesnake

Large eastern diamondback rattlesnake
Eastern diamondback rattlesnakes are the largest poisonous snake in Florida.

Chase D’animulls/Shutterstock.com

The Eastern Diamondback rattlesnake is the largest poisonous snake in Florida and also the most deadly in the United States. It is much more common and can be found in every county in Florida. Diamondbacks are capable of swimming, so they have made their way to some of the islands in and around the Keys. They are large bodied and are 5-6 feet long although the longest one on record was 8 feet. They are brown in color with dark brown diamond-shaped markings along their back. As rattlesnake, they have a rattle at the end of their tail they use to warn others.

If you came across one on a trail they would probably remain in a coiled position and you would have time to slowly back away. If they felt threatened, or you tried to approach one they may rattle their tail as a warning, raise the front of their body up and as a last resort strike. Although large, they are not aggressive, but if you get bitten, you should seek immediate medical attention.

2) Florida Cottonmouth

Side view of a Cottonmouth snake, ready to strike. The snake has a large spade-shaped head.
Cottonmouth snake can be found in lakes, rivers and waterways throughout Florida.

KF2017/Shutterstock.com

If you think you will be safe from poisonous snakes if you just stay off hiking trails you are wrong. What about swimming in a lake or river? You will have to look out for the Florida cottonmouth, or sometimes called a water Moccasin. While most of the snakes on our list prefer to be left alone and will give fair warning, cottonmouths are aggressive. They seem to have a short temper. They may coil back, open their mouths, and show their fangs before striking.

Cottonmouths are found throughout the state of Florida and can be found in lakes, rivers, swamps and retention ponds. They are a heavier bodied snake that can be 2-4 feet long and are black in color. They are called cottonmouths because of the white interior of their mouths. There are other water snakes that look similar that are not venomous but it is safest to stay away from all water snakes.  

1) Pygmy Rattlesnake

The Pygmy Rattlesnake may only be 1-2 feet long but they are poisonous.

Gerald A. DeBoer/Shutterstock.com

Don’t be fooled by the size of this little rattlesnake. Although it is the smallest rattlesnake, it is poisonous and can cause a painful bite. It is found throughout Florida and prefers forests and wooded areas. Pygmy rattlesnakes are thick, but shorter with most being 1-2 feet long. Their bodies are tan with dark brown splotches and a pinkish-brown stripe down the length of their back. The Pygmy rattlesnake is responsible for the most snake bites of poisonous snakes in Florida. It is common and because of its size, children often pick it up without knowing the snake is poisonous. Sometimes this results in the children getting bitten. These snakes are not aggressive and will flatten out to hide in the brush versus striking outright. If you do get bitten or your children does, you should seek immediate medical attention.

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About the Author

I'm a Wildlife Conservation Author and Journalist, raising awareness and suggesting actions we can all do to help wildlife. As a former elementary school teacher I have a love for learning and teaching. My goal is to get kids fired-up about animals. Learning about the animals we share this earth with makes life better. When I am not writing I am living the good life with my husband and six kids (we are down to two that are still at home...and our giant labradoodle, Tango!).

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