Snakes and spiders in Imperial County, California
Imperial County, home of El Centro, has 19 snake and 10 spider species on record, from 1,474 licensed snake and 136 spider records. Venomous species here: the sidewinder, the western diamondback rattlesnake, the southwestern speckled rattlesnake, the red diamond rattlesnake and the western black widow.
Are there venomous snakes or spiders in Imperial County?
Yes. The sidewinder: 207 licensed records, 11% of all California records of it. The western diamondback rattlesnake: 67 licensed records, 40% of all California records of it. The southwestern speckled rattlesnake: 9 licensed records, 3% of all California records of it. The red diamond rattlesnake: 6 licensed records, 1% of all California records of it. The western black widow: 4 licensed records, 0% of all California records of it.
What snakes are in Imperial County?
In all, 19 snake species are on the Imperial County list. The most recorded are the western ground snake (245), the sidewinder (207) and the western threadsnake (193). Imperial County holds more than half of all California records of the western ground snake and the checkered garter snake.
| # | Species | Records | Share of California records |
|---|---|---|---|
| 1 | Western ground snake Sonora semiannulata | 245 | 83% |
| 2 | Sidewinder venomous Crotalus cerastes | 207 | 11% |
| 3 | Western threadsnake Rena humilis | 193 | 29% |
| 4 | Western shovel-nosed snake Sonora occipitalis | 154 | 10% |
| 5 | Gopher snake Pituophis catenifer | 116 | 2% |
| 6 | Spotted leaf-nosed snake Phyllorhynchus decurtatus | 104 | 8% |
| 7 | Glossy snake Arizona elegans | 79 | 6% |
| 8 | Western diamondback rattlesnake venomous Crotalus atrox | 67 | 40% |
| 9 | Coachwhip Masticophis flagellum | 66 | 6% |
| 10 | Colorado desert shovel-nosed snake Chionactis annulata | 51 | 23% |
| 11 | Long-nosed snake Rhinocheilus lecontei | 33 | 3% |
| 12 | California kingsnake Lampropeltis californiae | 24 | 1% |
| 13 | Western patch-nosed snake Salvadora hexalepis | 24 | 4% |
| 14 | Checkered garter snake Thamnophis marcianus | 18 | 86% |
| 15 | Southwestern speckled rattlesnake venomous Crotalus pyrrhus | 9 | 3% |
| 16 | Desert nightsnake Hypsiglena chlorophaea | 6 | 5% |
| 17 | Red diamond rattlesnake venomous Crotalus ruber | 6 | 1% |
| 18 | Baja California lyre snake Trimorphodon lyrophanes | 4 | 2% |
| 19 | Northern three-lined boa Lichanura orcutti | 4 | 3% |
When are snakes out in Imperial County?
Observation records of snakes in Imperial County run mostly March through October, peaking in April with 23% of them; across California the peak is May.
What spiders are in Imperial County?
In all, 10 spider species are on the Imperial County list. The most recorded are Habronattus signatus (15), Habronattus tarsalis (9) and the California ebony tarantula (6).
| # | Species | Records | Share of California records |
|---|---|---|---|
| 1 | Habronattus signatus | 15 | 9% |
| 2 | Habronattus tarsalis | 9 | 4% |
| 3 | California ebony tarantula Aphonopelma eutylenum | 6 | 6% |
| 4 | Western spotted orbweaver Neoscona oaxacensis | 5 | 1% |
| 5 | Western black widow venomous Latrodectus hesperus | 4 | 0% |
| 6 | Syspira longipes | 3 | 7% |
| 7 | Giant crab spider Olios giganteus | 1 | 2% |
| 8 | Homalonychus theologus | 1 | 5% |
| 9 | Marbled cellar spider Holocnemus pluchei | 1 | 0% |
| 10 | Cahuilla ebony tarantula Aphonopelma xwalxwal | — | — |
When are spiders out in Imperial County?
Observation records of spiders in Imperial County run through most of the year, peaking in September with 24% of them; across California the peak is April.
What stands out in Imperial County
Species for which Imperial County holds a large share of all California records: the checkered garter snake, 86% (18 of 21); the western ground snake, 83% (245 of 296); the western diamondback rattlesnake, 40% (67 of 169); the western threadsnake, 29% (193 of 674); the Colorado desert shovel-nosed snake, 23% (51 of 226).
Common in California, not on the Imperial County list
Among the snakes most recorded across California, these do not reach the county list: the western terrestrial garter snake (21,830 statewide), the common garter snake (5,777 statewide), the western rattlesnake (5,224 statewide), the aquatic garter snake (3,727 statewide), the western aquatic garter snake (3,716 statewide) and the ring-necked snake (1,797 statewide). Few records here can mean the species is rare in the county, or that few people have looked.
Among the spiders most recorded across California, these do not reach the county list: the bold jumper (2,606 statewide), the half-edged wall jumping spider (2,178 statewide), Steatoda nobilis (1,914 statewide), the false black widow (1,201 statewide), the western lynx spider (1,123 statewide) and the Koch's wolf spider (1,020 statewide). Few records here can mean the species is rare in the county, or that few people have looked.
Harmless lookalikes in Imperial County
Rattlesnakes are on the county list, and so are harmless species often taken for them: the gopher snake. Coral snakes are not on the California list, but GBIF holds 3 coral snake records of any license in California (Sonoran coralsnake 3): treat any snake like this as venomous until identified. Harmless species often taken for them here: the long-nosed snake.
Imperial County among California counties
By licensed snake records Imperial County ranks 16th of 58 California counties with any.
Other California counties with their own page: San Diego County, Lassen County, Shasta County, Riverside County, San Bernardino County, Humboldt County, Sonoma County and San Mateo County.
The whole state: venomous species in California, all snakes, all spiders.
GBIF records read 2026-09-29. Listed: any license. Counted: CC0/CC BY only. How we count.