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Snakes and spiders in San Diego County, California

San Diego County has 29 snake and 119 spider species on record, from 9,077 licensed snake and 8,431 spider records. Venomous species here: the western rattlesnake, the red diamond rattlesnake, the sidewinder, the southwestern speckled rattlesnake, the brown widow, the western black widow and the desert recluse.

29snake species
119spider species
7venomous
Bitten in San Diego County? Call 911 for a venomous snakebite or any bite with trouble breathing. For advice on any bite or sting, call Poison Help at 1-800-222-1222 (free, 24/7, U.S.-wide). Do not cut the wound, suck out venom or use a tourniquet. General information, not medical advice. Do not handle or try to identify a snake or spider by this page; if unsure, treat it as venomous.

Are there venomous snakes or spiders in San Diego County?

Yes. The western rattlesnake: 1,368 licensed records, 26% of all California records of it. The red diamond rattlesnake: 626 licensed records, 68% of all California records of it. The sidewinder: 329 licensed records, 17% of all California records of it. The southwestern speckled rattlesnake: 73 licensed records, 27% of all California records of it. The brown widow: 161 licensed records, 21% of all California records of it. The western black widow: 124 licensed records, 10% of all California records of it. The desert recluse: 6 licensed records, 15% of all California records of it.

What snakes are in San Diego County?

In all, 29 snake species are on the San Diego County list. The most recorded are the western rattlesnake (1,368), the California kingsnake (817) and the gopher snake (764). San Diego County holds more than half of all California records of the red diamond rattlesnake, the Colorado desert shovel-nosed snake, the Baja California lyre snake and the coast nightsnake.

#SpeciesRecordsShare of California records
1Western rattlesnake venomous
Crotalus oreganus
1,36826%
2California kingsnake
Lampropeltis californiae
81731%
3Gopher snake
Pituophis catenifer
76411%
4Two-striped garter snake
Thamnophis hammondii
67041%
5Red diamond rattlesnake venomous
Crotalus ruber
62668%
6Spotted leaf-nosed snake
Phyllorhynchus decurtatus
56845%
7Glossy snake
Arizona elegans
42230%
8Western shovel-nosed snake
Sonora occipitalis
35724%
9Long-nosed snake
Rhinocheilus lecontei
34734%
10Sidewinder venomous
Crotalus cerastes
32917%
11Striped racer
Masticophis lateralis
30725%
12Western threadsnake
Rena humilis
28943%
13Ring-necked snake
Diadophis punctatus
24414%
14Coachwhip
Masticophis flagellum
21218%
15Rosy boa
Lichanura trivirgata
19448%
16Western patch-nosed snake
Salvadora hexalepis
16627%
17Colorado desert shovel-nosed snake
Chionactis annulata
16573%
18Baja California lyre snake
Trimorphodon lyrophanes
14378%
19Coast nightsnake
Hypsiglena ochrorhynchus
12956%
20Eastern racer
Coluber constrictor
1129%
21Southwestern speckled rattlesnake venomous
Crotalus pyrrhus
7327%
22Western black-headed snake
Tantilla planiceps
7338%
23Desert nightsnake
Hypsiglena chlorophaea
5650%
24California mountain kingsnake
Lampropeltis zonata
448%
25Common garter snake
Thamnophis sirtalis
421%
26Northern three-lined boa
Lichanura orcutti
4130%
27Western aquatic garter snake
Thamnophis couchii
291%
28Brahminy blindsnake introduced
Indotyphlops braminus
1223%
29Baja California coachwhip
Masticophis fuliginosus
5100%
Source: GBIF records located in San Diego County (GADM level 2), read 2026-09-29. Listed from records under any license; counts are CC0/CC BY only.

When are snakes out in San Diego County?

Observation records of snakes in San Diego County run mostly March through October, peaking in April with 22% of them; across California the peak is May.

January: 8 observation records (1%)JanFebruary: 44 observation records (3%)FebMarch: 180 observation records (14%)Mar14%April: 291 observation records (22%)Apr22%May: 291 observation records (22%)May22%June: 194 observation records (15%)Jun15%July: 84 observation records (6%)Jul6%August: 76 observation records (6%)AugSeptember: 63 observation records (5%)SepOctober: 51 observation records (4%)OctNovember: 25 observation records (2%)NovDecember: 10 observation records (1%)Dec

What spiders are in San Diego County?

In all, 119 spider species are on the San Diego County list. The most recorded are the silver argiope (537), Steatoda nobilis (228) and the Koch's wolf spider (213). San Diego County holds more than half of all California records of the silver argiope, the McCook's split wolf spider, Habronattus californicus and the California trapdoor spider.

#SpeciesRecordsShare of California records
1Silver argiope
Argiope argentata
53771%
2
Steatoda nobilis
22812%
3Koch's wolf spider
Alopecosa kochi
21321%
4Buttonhook leafbeetle jumping spider
Sassacus vitis
18122%
5Green lynx spider
Peucetia viridans
17146%
6Brown widow venomous introduced
Latrodectus geometricus
16121%
7
Dysdera crocata
12619%
8Western black widow venomous
Latrodectus hesperus
12410%
9McCook's split wolf spider
Schizocosa mccooki
11153%
10Spotted orbweaver
Neoscona crucifera
10727%
11Johnson jumper
Phidippus johnsoni
10111%
12
Drassyllus insularis
8745%
13
Habronattus californicus
8576%
14California trapdoor spider
Bothriocyrtum californicum
7566%
15False black widow
Steatoda grossa
726%
16
Marinarozelotes lyonneti
6289%
17
Mexigonus minutus
6270%
18
Anelosimus studiosus
60100%
19Longbodied cellar spider
Pholcus phalangioides
599%
20Western spotted orbweaver
Neoscona oaxacensis
539%
21
Cyclosa turbinata
4630%
22
Xysticus californicus
4549%
23
Zelotes gynethus
44100%
24Pecos brown
Aphonopelma steindachneri
4357%
25
Oxyopes tridens
4189%
26
Pardosa californica
4033%
27Banded garden spider
Argiope trifasciata
3913%
28Cribellate spider
Metaltella simoni
3810%
29Phoenix jumping spider
Phidippus phoenix
37100%
30Striped lynx spider
Oxyopes salticus
365%
31
Emblyna oregona
3492%
32Flatmesh weaver
Oecobius navus
3313%
33
Habronattus tarsalis
3315%
34
Syspira tigrina
3392%
35
Yorima angelica
3379%
36California ebony tarantula
Aphonopelma eutylenum
3232%
37
Callidalena tijuana
32100%
38
Habronattus elegans
3184%
39
Colonus hesperus
304%
40
Habronattus ustulatus
2944%
41California red jumping spider
Phidippus adumbratus
2817%
42Yellow sac spider
Cheiracanthium inclusum
2662%
43Whitebanded crab spider
Misumenoides formosipes
2540%
44
Habronattus pyrrithrix
243%
45
Cesonia trivittata
2388%
46Black-and-yellow argiope
Argiope aurantia
2215%
47
Eustala californiensis
2288%
48Bull-headed sac spider
Trachelas pacificus
2111%
49Icenogle trapdoor spider
Aptostichus icenoglei
2191%
50Bold jumper
Phidippus audax
201%
51Desert grass spider
Agelenopsis aperta
2033%
52Bark lynx spider
Hamataliwa grisea
1954%
53Western parson spider
Herpyllus propinquus
1910%
54Cabrillo Monument trapdoor spider
Aptostichus cabrillo
18100%
55Gray house spider
Badumna longinqua
175%
56Hirsute paradise spider
Habronattus hirsutus
178%
57Ribbon jumping spider
Metacyrba taeniola
177%
58
Heser nilicola
1650%
59
Phidippus nikites
1647%
60
Syspira longipes
1637%
Source: GBIF records located in San Diego County (GADM level 2), read 2026-09-29. Listed from records under any license; counts are CC0/CC BY only.

When are spiders out in San Diego County?

Observation records of spiders in San Diego County run through most of the year, peaking in September with 14% of them; across California the peak is April.

January: 89 observation records (3%)JanFebruary: 140 observation records (5%)FebMarch: 183 observation records (7%)Mar7%April: 332 observation records (13%)Apr13%May: 232 observation records (9%)May9%June: 185 observation records (7%)Jun7%July: 306 observation records (12%)Jul12%August: 304 observation records (11%)Aug11%September: 361 observation records (14%)Sep14%October: 284 observation records (11%)Oct11%November: 145 observation records (5%)NovDecember: 87 observation records (3%)Dec

What stands out in San Diego County

Species for which San Diego County holds a large share of all California records: Callidalena tijuana, 100% (32 of 32); the Phoenix jumping spider, 100% (37 of 37); Zelotes gynethus, 100% (44 of 44); Anelosimus studiosus, 100% (60 of 60); Emblyna oregona, 92% (34 of 37); Syspira tigrina, 92% (33 of 36); the Icenogle trapdoor spider, 91% (21 of 23); Oxyopes tridens, 89% (41 of 46).

Common in California, not on the San Diego County list

Among the snakes most recorded across California, these do not reach the county list: the western terrestrial garter snake (21,830 statewide) and the aquatic garter snake (3,727 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 half-edged wall jumping spider (2,178 statewide). Few records here can mean the species is rare in the county, or that few people have looked.

Harmless lookalikes in San Diego 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 and the California mountain kingsnake. Widow spiders are on the county list, and so are harmless species often taken for them: the false black widow and the triangulate bud spider. Recluse spiders are on the county list, and so are harmless species often taken for them: the longbodied cellar spider.

San Diego County among California counties

By licensed snake records San Diego County ranks 1st of 58 California counties with any.

Other California counties with their own page: Lassen County, Shasta County, Riverside County, San Bernardino County, Humboldt County, Sonoma County, San Mateo County and Los Angeles 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.

About these numbers

A species is listed for a state once GBIF holds at least 10 records of it located inside the state by coordinates, under any license. Every count, share, month and county shown is computed only from records published under CC0 or CC BY, so a listed species can show few or no counted records. Monthly patterns show when people record snakes and spiders, which also reflects when people are outdoors. Venomous status follows taxonomy: pit vipers and coral snakes; widow and recluse spiders; the Arizona bark scorpion. Records filed under older names count for the species they belong to today. Full methodology.