Snakes and spiders in San Luis Obispo County, California
San Luis Obispo County, home of San Luis Obispo, has 16 snake and 33 spider species on record, from 1,491 licensed snake and 759 spider records. Venomous species here: the western rattlesnake and the western black widow.
Are there venomous snakes or spiders in San Luis Obispo County?
Yes. The western rattlesnake: 172 licensed records, 3% of all California records of it. The western black widow: 36 licensed records, 3% of all California records of it.
What snakes are in San Luis Obispo County?
In all, 16 snake species are on the San Luis Obispo County list. The most recorded are the two-striped garter snake (372), the gopher snake (280) and the western aquatic garter snake (199).
| # | Species | Records | Share of California records |
|---|---|---|---|
| 1 | Two-striped garter snake Thamnophis hammondii | 372 | 23% |
| 2 | Gopher snake Pituophis catenifer | 280 | 4% |
| 3 | Western aquatic garter snake Thamnophis couchii | 199 | 5% |
| 4 | Western rattlesnake venomous Crotalus oreganus | 172 | 3% |
| 5 | Western terrestrial garter snake Thamnophis elegans | 117 | 1% |
| 6 | Aquatic garter snake Thamnophis atratus | 69 | 2% |
| 7 | Common garter snake Thamnophis sirtalis | 69 | 1% |
| 8 | California kingsnake Lampropeltis californiae | 65 | 2% |
| 9 | Ring-necked snake Diadophis punctatus | 52 | 3% |
| 10 | Striped racer Masticophis lateralis | 37 | 3% |
| 11 | Coachwhip Masticophis flagellum | 14 | 1% |
| 12 | Glossy snake Arizona elegans | 11 | 1% |
| 13 | Long-nosed snake Rhinocheilus lecontei | 6 | 1% |
| 14 | Eastern racer Coluber constrictor | 5 | 0% |
| 15 | Coast nightsnake Hypsiglena ochrorhynchus | 4 | 2% |
| 16 | Sharp-tailed snake Contia tenuis | 4 | 0% |
When are snakes out in San Luis Obispo County?
Observation records of snakes in San Luis Obispo County run mostly March through September, peaking in April with 26% of them; across California the peak is May.
What spiders are in San Luis Obispo County?
In all, 33 spider species are on the San Luis Obispo County list. The most recorded are Steatoda nobilis (121), the western black widow (36) and the Bay Area blonde (34).
| # | Species | Records | Share of California records |
|---|---|---|---|
| 1 | Steatoda nobilis | 121 | 6% |
| 2 | Western black widow venomous Latrodectus hesperus | 36 | 3% |
| 3 | Bay Area blonde Aphonopelma iodius | 34 | 11% |
| 4 | Banded garden spider Argiope trifasciata | 26 | 9% |
| 5 | Koch's wolf spider Alopecosa kochi | 21 | 2% |
| 6 | Habronattus amicus | 20 | 22% |
| 7 | Beach-dwelling jumping spider Terralonus californicus | 15 | 16% |
| 8 | Johnson jumper Phidippus johnsoni | 14 | 2% |
| 9 | Dysdera crocata | 11 | 2% |
| 10 | Longbodied cellar spider Pholcus phalangioides | 9 | 1% |
| 11 | Western lynx spider Oxyopes scalaris | 9 | 1% |
| 12 | California red jumping spider Phidippus adumbratus | 8 | 5% |
| 13 | Gem-shaped orbweaver Araneus gemma | 8 | 10% |
| 14 | Ribbon jumping spider Metacyrba taeniola | 8 | 3% |
| 15 | Spotted orbweaver Neoscona crucifera | 8 | 2% |
| 16 | Cyclosa turbinata | 7 | 5% |
| 17 | False black widow Steatoda grossa | 7 | 1% |
| 18 | Schizocosa maxima | 7 | 27% |
| 19 | Striped lynx spider Oxyopes salticus | 7 | 1% |
| 20 | Colonus hesperus | 6 | 1% |
| 21 | Phidippus kastoni | 6 | 19% |
| 22 | Diaea livens | 5 | 12% |
| 23 | Gray house spider Badumna longinqua | 5 | 1% |
| 24 | Goldenrod crab spider Misumena vatia | 4 | 2% |
| 25 | Buttonhook leafbeetle jumping spider Sassacus vitis | 3 | 0% |
| 26 | Hairy tufted jumping spider Phidippus comatus | 3 | 2% |
| 27 | Bull-headed sac spider Trachelas pacificus | 2 | 1% |
| 28 | McCook's split wolf spider Schizocosa mccooki | 2 | 1% |
| 29 | Western parson spider Herpyllus propinquus | 2 | 1% |
| 30 | Green lynx spider Peucetia viridans | 1 | 0% |
| 31 | Marbled cellar spider Holocnemus pluchei | 1 | 0% |
| 32 | Phidippus nikites | 1 | 3% |
| 33 | Shoreline wolf spider Arctosa littoralis | 1 | 1% |
When are spiders out in San Luis Obispo County?
Observation records of spiders in San Luis Obispo County run through most of the year, peaking in October with 21% of them; across California the peak is April.
What stands out in San Luis Obispo County
Species for which San Luis Obispo County holds a large share of all California records: the two-striped garter snake, 23% (372 of 1,620); Habronattus amicus, 22% (20 of 89); the beach-dwelling jumping spider, 16% (15 of 92).
Common in California, not on the San Luis Obispo County list
Among the snakes most recorded across California, these do not reach the county list: the sidewinder (1,923 statewide) and the western shovel-nosed snake (1,482 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), Habronattus pyrrithrix (800 statewide) and the brown widow (776 statewide). Few records here can mean the species is rare in the county, or that few people have looked.
Harmless lookalikes in San Luis Obispo 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. Widow spiders are on the county list, and so are harmless species often taken for them: the false black widow. No recluse spiders reach the county list, but the desert recluse is on the California list: treat any spider like it as venomous until identified. Harmless species often taken for them here: the longbodied cellar spider.
San Luis Obispo County among California counties
By licensed snake records San Luis Obispo County ranks 15th 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.