Venomous Snakes in Arizona: What Actually Lives Here
14 venomous species out of 60 snakes recorded in the state. Live range maps, the real season, and the harmless lookalikes people kill by mistake.
14 venomous species in Arizona and roughly 77% of its snakes are harmlessSnakes in Arizona, by the numbers
Verified records, not folkloreArizona has more rattlesnake species than any other state, thirteen with verified records, plus the Sonoran coral snake. Their activity peaks with the July and August monsoon rather than in spring, which is the opposite of most of the country.
The 14 venomous snakes of Arizona
Every species below has verified, photograph-backed records in Arizona. The record counts come from iNaturalist and measure how often people find and photograph each snake, not how many there are: a species living in roadless country will always look rarer than one living in suburbs.
| Species | Group | Verified records |
|---|---|---|
| Western diamondback rattlesnake Crotalus atrox | Rattlesnake | 10,903 |
| Western black-tailed rattlesnake Crotalus molossus | Rattlesnake | 3,114 |
| Mojave rattlesnake Crotalus scutulatus | Rattlesnake | 2,366 |
| Sidewinder Crotalus cerastes | Rattlesnake | 1,234 |
| Tiger rattlesnake Crotalus tigris | Rattlesnake | 998 |
| Rock rattlesnake Crotalus lepidus | Rattlesnake | 774 |
| Arizona black rattlesnake Crotalus cerberus | Rattlesnake | 753 |
| Southwestern speckled rattlesnake Crotalus pyrrhus | Rattlesnake | 710 |
| Sonoran coral snake Micruroides euryxanthus | Coral snake | 587 |
| Ridge-nosed rattlesnake Crotalus willardi | Rattlesnake | 356 |
| Prairie rattlesnake Crotalus viridis | Rattlesnake | 259 |
| Western rattlesnake Crotalus oreganus | Rattlesnake | 237 |
| Twin-spotted rattlesnake Crotalus pricei | Rattlesnake | 210 |
| Western massasauga Sistrurus tergeminus | Rattlesnake | 6 |
Where each species has actually been found
Most pages about snake range publish the same drawn map, redrawn from a book. This one is built from verified records: pick a species and the coloured cells are places where somebody photographed one and an expert confirmed the identification. It updates as people keep logging records.
Coloured cells are verified Crotalus atrox records on iNaturalist, brighter where more have been logged. This is where people have found and photographed the species, so it thins out over roadless country and thickens around parks and towns. It is a record map, not a drawn range boundary. See the underlying records.
When Arizona snakes are actually out
Activity here does not follow the pattern most of the country does. Records climb slowly through spring and then jump with the July and August monsoon, when humidity, prey, and night-time temperatures all arrive at once. That is the opposite of the spring peak you would see in the Southeast.
What the chart counts. It counts records, and a record needs a snake and a person with a camera. April spikes in some states are a late-April bioblitz, not snakes. Switch the chart to the effort-adjusted view and each month is divided by all the research-grade observations logged in Arizona that month, which strips most of that out. Neither view is a population estimate.
The harmless snakes people kill by mistake
This is the part worth reading. Most “venomous snake in my yard” calls turn out to be a harmless species, and most bites happen to people trying to kill or move a snake rather than to people walking past one. Learning three lookalikes removes almost all of the risk and all of the panic.
In the United States, a rattle is a rattle: if it has one, it is a rattlesnake. Coral snakes are the only banded red-yellow-black snake in the country where red touches yellow. Head shape and pupil shape are unreliable. Plenty of harmless snakes flatten their heads into a triangle when frightened, and you should never be close enough to a snake to check its pupils.
Confused with the rattlesnake
Gopher snake or bullsnake
Pituophis catenifer
Hisses loudly, flattens its head into a triangle, and vibrates its tail in dry leaves to fake a rattle. It has no rattle, round pupils, and a much longer, more tapered tail.
Eastern hognose snake
Heterodon platirhinos
Flares its neck like a cobra, hisses, and then plays dead upside down with its tongue out. The upturned pig snout gives it away, and it has no rattle.
Confused with the coral snake
Scarlet kingsnake
Lampropeltis elapsoides
Red bands touch black bands, and the snout is red. On a coral snake the red bands touch yellow and the snout is black. The rhyme works in the United States and only in the United States.
Scarlet snake
Cemophora coccinea
Red saddles that do not wrap all the way around, over a plain white belly. Coral snake bands ring the whole body.
Where venomous snakes live in Arizona
Snakes are creatures of edges and cover: rock with crevices, water with banks, litter with rodents underneath. In Arizona the habitats that matter are Sonoran Desert bajadas, washes, and rocky slopes, sky-island canyons and pine-oak woodland in the southeast, Colorado Plateau canyon country in the north.
Sonoran Desert around Tucson and Phoenix
Western diamondbacks and Mojave rattlesnakes on bajadas and in washes, active mostly at night in summer.
Sky islands of the southeast
The richest rattlesnake fauna in the country: ridge-nosed, twin-spotted, rock, and black-tailed rattlesnakes in one range.
Grand Canyon
The Grand Canyon rattlesnake, a pink-tinted western rattlesnake found essentially nowhere else.
Making a yard less interesting to them
A snake in a yard is following food and cover. Take away the cover and the food follows: keep grass short at the edges, stack firewood off the ground and away from the house, close gaps under steps and sheds, and do not leave pet food or birdseed out overnight, because both feed the rodents that feed the snakes. Snake repellent powders and sonic stakes have repeatedly failed to work in trials; a tidy woodpile does.
If you meet one
Venomous snakebite is rare in the United States, treatable, and rarely fatal when someone gets to a hospital. The national bite and death figures that circulate all trace back to a single agency page.
Arizona venomous snake FAQ
The rest of your Arizona summer
More Southwest snake guides
Species lists, record counts, and monthly curves are research-grade observations from the iNaturalist API, read in your browser. They measure how often people find and photograph a species, not how many there are, and a species with no record here may still live here. Season windows are derived from those curves and are climatological typicals, not a forecast. See every record behind this page. If someone is bitten, go to a hospital. National picture: venomous snakes by state →
Hero image: “Western Diamondback Rattlesnake (Crotalus atrox)” — Gary Stolz, USFWS — Public domain