Now that summer has arrived in sunny San Diego, everyone wants to come out to enjoy the heat. Local snakes can be active this season just like us—emerging from their hiding spots to bask in the sun, hunt, and sometimes mate. Peak snake season in San Diego runs from April to June, but many snakes remain active in July and August.
You might encounter one on a hike or walk, in a local park or canyon, or even your own backyard , so make sure to brush up on your snake ID skills ! This guide wi ll help you quickly recognize some of San Diego’s most common snakes.
As you start exploring our county's snakes, be respectful of your surroundings. Do not attempt to touch or get too close to any wildlife, snake or not. Some of the defining characteristics outlined in this document are difficult to tell from far away, so instead of getting closer, take a picture from a healthy distance and try your ID skills at home.
Why Learn to Identify San Diego Snakes?
San Diego County is home to 65 native reptile species, of which 28 are species of snakes (27 local and 1 introduced). Knowing which is which helps to:
- Promote peaceful coexistence with native wildlife
- Encourage curiosity, not fear
- Ensure you can enjoy local hikes and nature outings with confidence
Here are 10 of the most commonly observed snakes in San Diego:
1. Southern pacific rattlesnake (Crotalus helleri) — Venomous
Photo from dblanco on iNaturalist
- Can have 27-34 dark blotches with light margins on its back.
- The blotches transition to band-like markings toward the tail.
- In adults, the segment of the rattle that’s closest to its body is often black, brown, tan, or mottled. In juveniles, it’s yellow.
- They often become darker as they get older.
Fun fact: the southern pacific rattlesnake is still considered a subspecies of the western rattlesnake by some experts.
2. Gopher snake (Pituophis catenifer) — Non-venomous
Photo by Adam G. Clause.
- The scales on its back are prominently keeled, which means that rather than being smooth, the scales have a ridge down the center.
- The bottom side of the snake is usually off-white, yellow, or yellowish orange. Sometimes it has dark spots, sometimes it doesn’t.
- They have a dark, vertical mark that runs from the top of its head (near its eyes) to the top of its jaw on each eye (it looks like eyeliner—check it out in the picture!).
3. California king snake (Lampropeltis californiae) — Non-venemous
Photo by Adam G. Clause. (Banded morph)
Photo by Adam G. Clause. (Striped morph)
- There are two variations: banded and striped. Both variations have smooth scales on their back.
- Banded morph
- Dark brown (nearly black) to medium brown coloration on its back with white, cream, or yellow rings.
- Its belly is usually checkered.
- Striped morph
- Can range from fully striped to a combination of rings, stripes, and speckling.
- Most of the time their bellies are all-black.
3. Red diamond rattlesnake (Crotalus ruber) — Venemous
Photo by Adam G. Clause.
- It has blotches with light margins on its back.
- The blotches abruptly change to black and white (or light gray) tail rings.
- The scales on its mid-back are keeled, which means that rather than being smooth, the scales have a ridge down the center.
- Its belly is white to cream, sometimes with brown or grayish-brown coloration.
5. Striped racer or California whipsnake (Masticophis lateralis) — Non-venomous
Photo by Brad Hollingsworth.
- Long-tailed, slender, and fast-moving.
- Its back is brown or black and fades into a brown tail.
- It has very prominent cream or yellow stripes on its sides from its neck to the bottom area of the tip of their tail, where they fade.
- Its belly is cream or yellow, sometimes with orange or pink coloration in the front part of their bellies. They have spotting on their throat.
6. Two-striped gartersnake (Thamnophis hammondii) — Non-venomous
Photo by Brad Hollingsworth.
- Dark brown to olive-brown snake with a pale lengthwise stripe on each flank. Sometimes it has dark blotches that frame the top of its back.
- Its scales on its mid-back are keeled, which means that rather than being smooth, the scales have a ridge down the center.
- Its belly can be salmon, yellow-orange, or gray.
7. Coastal rosy boa (Lichanura orcutti) — Non-venomous
Photo by Adam G. Clause.
- Slow-moving with a blunt tail.
- The pattern on its back varies regionally. The stripes on its back can be smooth or jagged (like the one in this photo), or the entire body can be dark gray.
- The coloration on its belly is similar to or slightly lighter than the color of its back. The bellies have irregular spots or mottling that match the color of the stripes on its back.
- Males have pelvic spurs, which are tiny appendages at the base of their tail.
Fun fact: pelvic spurs are remnants of the hind limbs of the snake's legged ancestors! Also, it was named after past Nat scientist Charles Russell Orcutt.
8. Sidewinder (Crotalus cerastes) — Venomous
Photo by Adam G. Clause.
- Has a distinct, horn-like scale above each eye.
- It has keeled scales, which means that rather than being smooth, the scales have a ridge down the center.
- Its colors are muted and can be buff, tan, or pinkish (usually matching the local substrate or sand).
- It has blotches on its back in various shades of brown or brownish-orange that vary in size.
- Its belly is pale and unmarked, though it may have some dark markings on the bottom side of its tail.
9. Ring-necked snake (Diadophis punctatus) — Non-venomous
Photo by Bradford Hollingsworth.
- It’s small, slender, and has smooth scales.
- Its back is olive, gray-green, or dark gray with a bright red or orange ring around the neck (juveniles have yellowish rings).
- Its belly is orange, and is often a deeper shade on the underside of its tail (which can have scattered black spots).
10. Southwestern speckled rattlesnake (Crotalus pyrrhus) — Venomous
Photos by Adam G. Clause.
- Very variable in coloration closely matching local rock formations: cream, tan, gray, brown, orange, or reddish pink.
- Its back has 23-43 blotches that can often vary in shape and level of contrast (some are more noticeable than others).
- The coloration transitions to 4-9 rings on its tail which tend to be lighter than the ground color. The last few rings are black.
- Its belly is off-white, light gray, or salmon. Sometimes it has darker markings, and sometimes it doesn’t.
- Its scales on its mid-back are keeled, which means that rather than being smooth, the scales have a ridge down the center
Want to learn more?
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Discover The Nat: Glass Photographs on Zooniverse
Help The Nat identify desert snake species and contribute to herpetology research using historic glass plate photographs from our research library collection!
Posted by Julie Frakes Gattenio, Research Library & Archives Intern; Adam G. Clause, Herpetology Collections Manager; Paula Sternberg Rodríguez, Science Communications Manager; Ariel Hammond, Director of Research Library and Archives.
