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Snakes and spiders in Napa County, California

Napa County, home of Napa, has 10 snake and 24 spider species on record, from 431 licensed snake and 671 spider records. Venomous species here: the western rattlesnake and the western black widow.

10snake species
24spider species
2venomous
Bitten in Napa 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 Napa County?

Yes. The western rattlesnake: 27 licensed records, 1% of all California records of it. The western black widow: 73 licensed records, 6% of all California records of it.

What snakes are in Napa County?

In all, 10 snake species are on the Napa County list. The most recorded are the aquatic garter snake (111), the gopher snake (67) and the ring-necked snake (63).

#SpeciesRecordsShare of California records
1Aquatic garter snake
Thamnophis atratus
1113%
2Gopher snake
Pituophis catenifer
671%
3Ring-necked snake
Diadophis punctatus
634%
4Sharp-tailed snake
Contia tenuis
526%
5Common garter snake
Thamnophis sirtalis
270%
6Western rattlesnake venomous
Crotalus oreganus
271%
7California kingsnake
Lampropeltis californiae
251%
8Western terrestrial garter snake
Thamnophis elegans
190%
9Striped racer
Masticophis lateralis
161%
10Eastern racer
Coluber constrictor
141%
Source: GBIF records located in Napa 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 Napa County?

Observation records of snakes in Napa County run mostly November through May, peaking in April with 35% of them; across California the peak is May.

January: 6 observation records (5%)JanFebruary: 7 observation records (6%)Feb6%March: 17 observation records (15%)Mar15%April: 39 observation records (35%)Apr35%May: 25 observation records (23%)May23%June: 2 observation records (2%)JunJuly: 0 observation records (0%)JulAugust: 1 observation record (1%)AugSeptember: 4 observation records (4%)SepOctober: 3 observation records (3%)OctNovember: 4 observation records (4%)NovDecember: 2 observation records (2%)Dec

What spiders are in Napa County?

In all, 24 spider species are on the Napa County list. The most recorded are the false black widow (106), Steatoda nobilis (85) and the western black widow (73).

#SpeciesRecordsShare of California records
1False black widow
Steatoda grossa
1069%
2
Steatoda nobilis
854%
3Western black widow venomous
Latrodectus hesperus
736%
4Zebra spider
Salticus scenicus
6220%
5
Dysdera crocata
518%
6Johnson jumper
Phidippus johnsoni
425%
7Marbled cellar spider
Holocnemus pluchei
334%
8Western lynx spider
Oxyopes scalaris
172%
9Koch's wolf spider
Alopecosa kochi
162%
10Half-edged wall jumping spider
Menemerus semilimbatus
151%
11Western spotted orbweaver
Neoscona oaxacensis
153%
12Bold jumper
Phidippus audax
130%
13Striped lynx spider
Oxyopes salticus
112%
14Longbodied cellar spider
Pholcus phalangioides
91%
15Buttonhook leafbeetle jumping spider
Sassacus vitis
81%
16Gray house spider
Badumna longinqua
62%
17Black-and-yellow argiope
Argiope aurantia
32%
18California turret spider
Atypoides riversi
31%
19
Colonus hesperus
30%
20Garden spider
Araneus diadematus
31%
21Hairy tufted jumping spider
Phidippus comatus
32%
22McCook's split wolf spider
Schizocosa mccooki
31%
23Banded garden spider
Argiope trifasciata
10%
24California funnel-web spider
Calisoga longitarsis
——
Source: GBIF records located in Napa 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 Napa County?

Observation records of spiders in Napa County run through most of the year, peaking in November with 18% of them; across California the peak is April.

January: 87 observation records (14%)Jan14%February: 21 observation records (3%)FebMarch: 93 observation records (15%)Mar15%April: 38 observation records (6%)AprMay: 53 observation records (8%)May8%June: 35 observation records (5%)JunJuly: 43 observation records (7%)Jul7%August: 47 observation records (7%)Aug7%September: 36 observation records (6%)SepOctober: 27 observation records (4%)OctNovember: 114 observation records (18%)Nov18%December: 47 observation records (7%)Dec7%

What stands out in Napa County

Species for which Napa County holds a large share of all California records: the zebra spider, 20% (62 of 304).

Common in California, not on the Napa County list

Among the snakes most recorded across California, these do not reach the county list: the western aquatic garter snake (3,716 statewide), the sidewinder (1,923 statewide), the two-striped garter snake (1,620 statewide), the western shovel-nosed snake (1,482 statewide) and the glossy snake (1,425 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: 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 Napa County

Rattlesnakes are on the county list, and so are harmless species often taken for them: the gopher 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.

Napa County among California counties

By licensed snake records Napa County ranks 33rd 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.

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.