Wolf spider bites in Colorado

Colorado has 225 verified wolf spider records in the GBIF biodiversity database — one of the highest counts in the country. Sightings concentrate in July to October. The bite itself appears immediate sharp pain and lasts usually resolves in a few days.

Wolf spider in Colorado — semi-arid highland climate
Verified records225
Peak sightingsJuly to October
State bite seasonMay to September
Activenight — this spider hunts on the ground rather than building a web
Habitatlawns, gardens, garages and basements across the whole country
Bite appearsimmediate sharp pain

Identifying it in Colorado

Large, hairy, fast, and frightening at close range — but medically unremarkable. Wolf spiders bite defensively when pressed against skin, the pain is immediate and sharp, and the reaction stays local. Their size makes them the spider most often blamed for bites they did not cause.

Locally, the species most often confused with it are honey bee sting, paper wasp sting, bald-faced hornet sting — all of which are also recorded in Colorado.

Seek medical care if

  • spreading redness, warmth or pus over the following days
  • fever

What else it could be in Colorado

These are recorded in Colorado too and are the ones most often confused with it here. The differences below are the ones that actually separate them.

Wolf spider biteBrown recluse spider biteBlack widow spider bite
Patternsingle site single sitesingle site
Where on bodyhands, feet, lower legs torso under clothing, upper arms, thighs — often where clothing was put on with the spider insidehands, forearms, legs — usually where a hand reached into a dark space
Appearsimmediate sharp pain often painless at firsta sharp pinprick, then pain building over 30 to 60 minutes
Records here225 188

Season in Colorado specifically

Records in Colorado concentrate in July to October, which is what local sighting data shows rather than a national average — seasonality shifts substantially with latitude. The general bite season in Colorado runs May to September.

Because lawns, gardens, garages and basements across the whole country, exposure in Colorado tends to be concentrated in specific places rather than spread evenly — which is why a bite history ("where were you in the 24 hours before?") narrows the answer faster than the appearance of the mark.

Care

  1. wash with soap and water
  2. cold pack, elevate, over-the-counter pain relief
  3. watch for signs of infection over the next few days

Avoiding them in Colorado

Questions

When are wolf spiders active in Colorado?

Colorado records peak in July to October. The general bite season in Colorado runs May to September.

Are they common in Colorado?

Colorado accounts for 225 verified records in GBIF, ranking it 3rd among states for this species. Records reflect reporting effort as well as abundance.

What does the bite look like?

a red swollen area with two faint puncture points, red. Single site.

Get a photo assessment in the app

Everything above is free to read. The app adds what a page cannot: point your camera at the bite and get an assessment of the most likely cause, a severity read, and a day-by-day care plan — including the specific signs that mean you should be seen.

Download for iPhone — free

iPhone and iPad. Free to download.