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Venomous Snakes in New Hampshire: 1 Species & How to Tell

Last checked November 3, 2026 against official sources.

On this page
  1. The venomous snake
  2. Lookalikes
  3. When they are active
  4. If you are bitten or stung
  5. How to report
  6. Common questions
  7. About this list
  8. Sources

New Hampshire has 1 venomous snake named by official sources: Timber Rattlesnake. It is labelled venomous by New Hampshire Fish and Game Department.

The venomous snake of New Hampshire

Recognize them from a distance; a photo cannot confirm that a snake is safe. Identifying animals safely.

Timber Rattlesnake
Photo: NPS Photo · Public domain · Wikimedia Commons

Timber Rattlesnake

Crotalus horridus

Venomous per New Hampshire Fish and Game Department

Danger to people
“The bite of this snake can actually be quite dangerous” Northern New England Poison Center
Size
Most adults 36 to 60 inches (3 to 5 feet); record 74.5 inches.
How to recognize it
  • Black tail ending in a rattle
  • Heat-sensing pit between nostril and eye
  • Large, thick head distinct from the neck; cat-like vertical pupil
Where in New Hampshire
Historically ranged from Massachusetts border up to the White Mountains. Currently there is only one known population in NH. New Hampshire Fish and Game Department
Conservation
NH endangered; Species of Greatest Conservation Need
What the sources say

Venom: “New Hampshire has only one venomous snake, the timber rattlesnake, which is protected by law.” (New Hampshire Fish and Game Department)

Habitat: Rocky, south-facing hillsides in wooded areas that are exposed to an abundance of sunlight. Rock ledges and outcroppings on hilltops are used for basking. Deep rock crevices are used as den sites for hibernation. During summer their habitat expands to brushy, forested areas where they often bask in sunspots. Males may travel several miles from den sites during summer and return in the fall. (New Hampshire Fish and Game Department)

Full Timber Rattlesnake guide

See all 11 snakes, venomous and not, on New Hampshire snakes.

Snakes people confuse

Black Racer or Timber rattlesnake?

Black Racer
Photo: Everglades NPS from Homestead, Florida, United States · Public domain · Wikimedia Commons

Black Racer Non-venomous

Timber rattlesnake
Photo: NPS Photo · Public domain · Wikimedia Commons

Timber rattlesnake Venomous

NH Fish and Game: the rattlesnake has a blunt rattle, is thicker, and has keeled scales and a triangular head.

Photos show typical adults; individuals vary. Never get close to compare.

When venomous snakes are active in New Hampshire

Records of snakes in New Hampshire peak in May to August. They show when people record snakes, not how many there are (about month bars).

450 records of snakes in New Hampshire by month (GBIF, CC0 and CC BY records).

If you are bitten or stung

Call 911 or Poison Help at 1-800-222-1222 right away. Poison Help connects you to your local poison center, any time of day.

Official advice from New Hampshire Fish and Game Department:

How to report

NH Fish and Game Wildlife Division (603) 271-2461; Law Enforcement (603) 271-3361. Invasive insects: NHBugs reporting form (nhbugs.org/reporting-form). Stranded marine animals: Seacoast Science Center (603) 997-9448 or the Northeast hotline (866) 755-6622. Sharks: Northeast Shark Hotline (401) 859-1043. New Hampshire Fish and Game Department

Common questions

About this list

The species list comes from Snakes of New Hampshire; Species Occurring in NH (New Hampshire Fish and Game Department, Internet Archive capture 2025-08-07 of the undated official page). 11 more entries come from other official sources named on each card.

Venom labels come only from official sources and link to them; "Not stated" never means harmless. How labels work.

Sources

  1. Snakes of NH (old site page). New Hampshire Fish and Game Department. archived copy, captured August 1, 2023; checked November 3, 2026.
    Quoted passages (2)
    “New Hampshire has only one venomous snake, the timber rattlesnake, which is protected by law.”
    “If you think you see a timber rattlesnake, please leave it alone, and let us know. There is no reason to kill a New Hampshire snake.”
  2. Snakes of New Hampshire. New Hampshire Fish and Game Department. archived copy, captured August 7, 2025; checked November 3, 2026.
    Quoted passages (1)
    “There are 11 species of snakes that are native to New Hampshire.”
  3. Timber Rattlesnake (Species Occurring in NH). New Hampshire Fish and Game Department. archived copy, captured November 3, 2026; checked November 3, 2026.
    Quoted passages (1)
    “…give birth to live young in the fall before returning to the den to hibernate from November until May.”
  4. Is that snake or spider poisonous? Northern New England Poison Center. Posted July 10, 2013; checked November 3, 2026.
    Quoted passages (1)
    “The bite of this snake can actually be quite dangerous”
  5. Common Garter Snake (Species Occurring in NH). New Hampshire Fish and Game Department. archived copy, captured June 3, 2025; checked November 3, 2026.
  6. Northern Water Snake (Species Occurring in NH). New Hampshire Fish and Game Department. archived copy, captured June 3, 2025; checked November 3, 2026.
    Quoted passages (1)
    “…water moccasin or cottonmouth (not a NH species)”
  7. Northern Ringneck Snake (Species Occurring in NH). New Hampshire Fish and Game Department. archived copy, captured August 5, 2025; checked November 3, 2026.
  8. Black Racer Snake (Species Occurring in NH). New Hampshire Fish and Game Department. archived copy, captured June 3, 2025; checked November 3, 2026.
  9. Eastern Milk Snake (Species Occurring in NH). New Hampshire Fish and Game Department. archived copy, captured June 3, 2025; checked November 3, 2026.
  10. Eastern Hognose Snake (Species Occurring in NH). New Hampshire Fish and Game Department. archived copy, captured June 3, 2025; checked November 3, 2026.
  11. Brown Snake (Species Occurring in NH). New Hampshire Fish and Game Department. archived copy, captured June 3, 2025; checked November 3, 2026.
  12. Northern Red Bellied Snake (Species Occurring in NH). New Hampshire Fish and Game Department. archived copy, captured June 23, 2025; checked November 3, 2026.
  13. Ribbon Snake (Species Occurring in NH). New Hampshire Fish and Game Department. archived copy, captured June 23, 2025; checked November 3, 2026.
  14. Smooth Green Snake (Species Occurring in NH). New Hampshire Fish and Game Department. archived copy, captured June 3, 2025; checked November 3, 2026.
  15. Wildlife FAQs. New Hampshire Fish and Game Department. archived copy, captured August 1, 2023; checked November 3, 2026.
    Quoted passages (1)
    “Wildlife Division - (603) 271-2461”
  16. GBIF.org occurrence records, human observations licensed CC0 1.0 or CC BY 4.0 only, accessed November 3, 2026. The datasets behind these counts are listed on our Sources page.