11 Most Venomous Rattlesnake Species in the World

Rattlesnakes are very well recognized venomous snakes, and here we have listed 11 most venomous rattlesnake species in the world. Rattlesnakes are native snakes to the Americas, being spread from Canada throughout Central and South America. Rattlesnakes count 36 species with many subspecies (the figure ranging between 65 and 70) and many regional variations in coloration.

Rattlesnakes belong to the group of snakes known as pit vipers, named like that because of special pits between their eyes and nostrils. Those pits have the role of sensing the differences in heat, by which pit vipers can detect their prey. Rattlesnakes are divided into two genera – Crotalus and Sistrurus, which are terms derived from the Greek language referring to their rattles. Rattlesnakes of Sistrurus genus are more primitive forms and inhabit southeastern parts of the Northern America, where many of the most venomous rattlesnakes in the world dwell, while Crotalus rattlesnakes are more advanced and more numerous, representing the majority of rattlesnakes and are spread from Canada to Argentina.

These snakes are unmistakably recognized by their rattles. Rattles have evolved from modified tail scales, and represent hollow segments of modified scales made of keratin. By contracting special muscles which these snakes have developed, rattle segments rub against each other producing clattering sound.

Some common physical characteristics of rattlesnakes, apart from the rattle are, broad triangular head, vertical pupils, usually large thick body, large fangs that fold when the snake opens its mouth, which can gape up to 180 degrees. Their scales are usually ridged, and although their coloration varies, many rattlesnake species have diamond-like patterns.

Having met the main characteristics of rattlesnakes, the question now is how to decide which rattlesnake species is the most venomous one? The method that scientists agree on how to decide which venom is the strongest one is the unit that shows the amount of venom needed to kill a living creature. That unit is called LD50, where LD stands for a lethal dose, and 50 for the 50% of kills per test sample (in this case laboratory mice). It is expressed in units that represent how much milligrams of venom is needed per kilogram of the victim in order to kill it. We have followed the data given from the Untamed Science and the Australian Venom research Unit. We have compared LD50 values and made this list in order that follows LD50 values – the lower the LD50 value, is the stronger the venom is. So, this list refers to rattlesnake venom strength, not the lethality in humans and other animals.

If you are eager to find out which other snakes apart from rattlesnakes are the most venomous, you can check our list of 20 Most Venomous Snakes in the World. Rattlesnakes are highly venomous snakes, and many do inflict bites to humans, sometimes even with the lethal outcome, but generally, if left alone, these snakes will not attack first and will try to avoid contacts. That is why they have their rattles on the first place, to warn the intruders to keep away. Let’s now go through most venomous rattlesnake species in the world that can be met.

11. Red diamond rattlesnake, red rattlesnake (Crotalus ruber)

LD50: 3.7

This species is native to Mexico and the southwestern United States, commonly spread throughout California. It dwells in various habitats, from rocky ocean coasts, desert scrub, to pine woodlands. Body length usually does not exceed 55 inches, and males are slightly larger than females. Coloration is brown reddish, hence the name, with diamond shaped pattern bordered with lighter colors.

10. Massasauga, ground rattlesnake, black snapper, spotted rattler, swamp rattlesnake,  (Sistrurus catenatus)

LD50: 2.9

This snake ranks 10th in our list of most venomous rattlesnake species in the world. It inhabits a wide range of habitats, from Texas to Canada, preferring wetlands from fall to spring, and then moves to drier uplands during summer. Since it inhabits a wide range of territories, it has been given many common names. It is rather a short species, with the average length of 19-27 inches. Their coloring offers a nice camouflage, being grayish with darker brown blotches and two rows of lined dots of darker color. Its name means “the great river mouth” in the Ojibwa language and refers to marshy grasslands around river deltas that these snakes inhabit.

9. Pygmy rattlesnake, ground rattlesnake, leaf rattler (Sistrurus miliarius)

LD50: 2.8

This species is native to marshes, floodplains and forests of southeast of the United States, including Florida, up to Missouri and southern Kentucky, west to Oklahoma and Texas. It is a small species, with average length 15-24 inches, and vividly colored. Its base color is light blue or gray with distinct brownish and orange rounded stains. Although according to the venom strength it belongs to the group of the most venomous rattlesnakes in the world, its bite is not deadly to humans, since it produces very small portions of venom.

8. Sidewinder, horned rattlesnake (Crotalus cerastes)

LD50: 2.6

We are continuing our list of most venomous rattlesnake species in the world wit the species that is native to Middle and North America. It inhabits Mexico and southern half of the United States. It dwells in sandy and desert terrains, and can be found up to 1.800 m asl, but it often inhabits lower altitudes. They got their name after the specific way in which they move, being specialized in moving on the loose desert sand, leaving the J-shaped traces behind them. They are small species, varying between 40 and 70 inches.

7. Western diamondback rattlesnake, coon tail, Arizona diamond rattlesnake, Texas diamondback  (Crotalus atrox)

LD50: 2.2

This snake species is present in the southern parts of the North America and throughout Central America. It is a snake with many common names, since it often encounters humans, and whose bite can be fatal, and considered to be among very venomous rattlesnake species in the world. These snakes prefer arid and semi-arid environments, like deserts, shrublands, plains, but also forests and coastal prairies. They usually grow around 6 feet, are brownish in color and have diamond shaped pattern.

6. Eastern diamondback rattlesnake (Crotalus adamanteus)

LD50: 1.2

Eastern diamondback rattlesnake inhabits southeastern parts of the US. Apart from being among most venomous rattlesnake species in the world, it is also the largest rattlesnake species, not so because of its length (between 30 and 75 inches), but its weight (5-10 pounds on average). It also has very long fangs, about 1 inch in length which adds to their fearsome looks. It injects a very big dose of venom when bites, around 410 mg per bite, which makes them highly dangerous.

5. Western rattlesnake, prairie rattlesnake, Great Plains rattlesnake (Crotalus viridis)

LD50: 1.01

This rattlesnake ranks 5th in our list of most venomous rattlesnake species in the world. It has a huge range of distribution, it reaches up from southern parts of Canada to Mexico, and it is considered to be most widely spread rattlesnake in the US, where it inhabits areas around the Great Plains to the Rocky Mountains. They reach around 4 feet in length on average. They vary in color, being gray, olive green, covered in speckles which melt into stripes in the lower part of the body. They are rare species of rattlesnakes that produce the Mojave toxin (see further on the list), which makes them very dangerous, though encounters with humans are rare.

4. Twin-spotted rattlesnake, Price’s rattlesnake, Arizona twin-spotted rattlesnake (Crotalus pricei)

LD50: 0.95

This rattlesnake ranks 4t hin our list of most venomous rattlesnake species in the world. It is found in Arizona and Mexico, where it inhabits highest altitudes of all other rattlesnakes up to 2,900 m above sea level. It inhabits coniferous forests and rocky areas. They are small species (around 20-24 inches in length), gray and bluish in color with small brownish stains.

3. Mojave rattlesnake (Crotalus scutulatus)

LD50: 0.18

We are continuing our list of most venomous rattlesnake species in the world with Mojave rattlesnake that inhabits southwestern states of the US and central Mexican territories. It prefers arid areas, high altitude deserts and sparse bushes or semi grasslands. It is a medium sized snake (about 2 – 4 feet long), but thick-bodied species. They are sometimes greenish colored, and thus are also known as Mojave green rattlesnakes. They have diamond patterns on their dorsal (back) side, which makes them often mistaken for western diamond rattlesnake, since they inhabit same regions. Mojave rattlesnake’s toxin is highly venomous and very dangerous to humans.  Even though it is not in the first place on our list of most venomous rattlesnakes in the world, this snake has one of the most powerful venoms among rattlesnakes. The special mix of toxins in its venom is unique among rattlesnakes that became known as the Mojave toxin.

2. Neotropical rattlesnake, South American rattlesnake, Yucatan rattlesnake (Crotalus durissus)

LD50: 0.17

This snake is distributed throughout Central and South American continent except for the Andes Mountains. Though it prefers drier habitats, like deserts, savannahs and grasslands, it can also be found in different ecosystems such as forests.  It has many common names, since it is much seen and encountered by people. It is a large snake, being around 4.9 feet long on average. There are several subspecies of this snake, but nevertheless, they have same diamond shaped pattern on the dorsal (back) side, and the coloration varies from region to region.

1. Tiger rattlesnake (Crotalus tigris)

LD50: 0.06

The number one of the most venomous rattlesnake species in the world is the tiger rattlesnake. This snake inhabits predominantly drier environments, rocky arid canyons and savannahs and grasslands on rather higher altitudes from 1,000-1,500 meters above sea level. It is present in southern parts of Arizona and in Sonora desert. Tiger rattlesnakes are recognizable for their small heads, and are considered to be rattlesnakes with the smallest heads and big rattles. The average length is around 24 inches, with males being slightly larger. They are nicely camouflaged into the environment as their coloration varies. Interestingly, tiger rattlesnake is the only rattlesnake to have crossband pattern on the ventral side (belly) of the body. On the dorsal (back) side they have darker bands. This snake produces a very small portion of venom (about 10 mg), but it is highly toxic.