Are There Black Widows in Michigan?
No, Black Widows are not established in Michigan. The state's cold winters make it impossible for this heat-loving spider to survive outdoors year-round. While Black Widows are found across the southern and central United States, Michigan's climate is far too cold for established populations. Recognizing harmless Michigan spiders helps ease worry about yard work.
By Tim, founder of Easy Street Markets. I maintain the wildlife database and verify every animal and source myself. Updated July 22, 2026.
Northern Black Widow · Joseph McPhail CC BY
Western Black Widow · Rebecca Ray CC BY
Western Black Widow · Michael Eisen CC BY
- 4
- species recorded
- 80
- GBIF records
- June, July, August
- peak months
Yes, black widows are in Michigan. Next you'll want:
Real sighting data, source iNaturalist
131 verified observations on iNaturalist of black widow have been recorded in Michigan, most often in June, July, August.
When black widow are recorded in Michigan
No, Black Widows are not established in Michigan. The state's cold winters make it impossible for this heat-loving spider to survive outdoors year-round. While Black Widows are found across the southern and central United States, Michigan's climate is far too cold for established populations. Recognizing harmless Michigan spiders helps ease worry about yard work.
Are they in Michigan?
Black Widows are not established anywhere in Michigan. The state's extremely cold winters, particularly in the Upper Peninsula but also throughout the Lower Peninsula, make it impossible for this heat-loving spider to survive outdoors year-round. Temperatures regularly drop well below freezing and remain there for months. Black Widows require warm conditions to complete their life cycle, and Michigan does not provide those conditions. Black Widows are found in established populations across the southern and central United States, from the mid-Atlantic states southward and westward. Michigan is well outside this range.Black Widows in Michigando not occur naturally. While an individual Black Widow might theoretically arrive in a shipment, such events are extremely rare.Michigan wildliferemains free of this spider.
How dangerous is it?
A Black Widow bite is medically significant and deserves medical attention, though deaths are extremely rare. The venom affects the nervous system and causes muscle pain, cramping, and sweating. Symptoms typically begin within one to several hours of the bite. Most healthy adults experience painful muscle cramping that gradually improves over hours to days, particularly with medical care. Very young children, elderly people, and those with heart disease or high blood pressure face higher risk of severe reactions. Severe symptoms may include intense muscle pain, tremors, profuse sweating, nausea, and general malaise. The bite itself is often painless, and many people do not realize they have been bitten until symptoms appear.Learn about spider safety.
How to recognize one
Black Widows are small spiders, about the size of a large pea in body length, not counting their legs. They are jet black or very dark brown with a shiny appearance. The most distinctive feature is a bright red or orange hourglass marking on the underside of the abdomen. Some Black Widows also display red spots on the upper side of their abdomen. The female is significantly larger than the male and is the one more likely to bite if threatened. These spiders spin webs in dark, sheltered places such as woodpiles, dense brush, and the corners of garages or sheds. They are sedentary spiders that remain in one spot rather than chasing prey across open ground.Learn more from our wildlife safety guides.
What to do if you are bitten or stung
Remain calm and do not panic. Wash the bitten area gently with soap and water. Remove any tight rings, bracelets, or jewelry from the area, as mild swelling can develop. Sit or lie down and keep the bitten limb as still as possible. Elevate the affected limb if you can to help reduce swelling. Do not apply a tourniquet or tie any tight bandage around the limb. Do not cut, squeeze, or attempt to suck out venom. Do not apply ice directly to the skin, though a cool cloth may provide comfort. Seek medical attention immediately, even if symptoms seem mild, so doctors can monitor your condition. Contact Poison Control for guidance or call 911 if you have chest pain or severe shortness of breath. Michigan hospitals and urgent care centers are well equipped to handle spider bites. This is general information, not medical advice; if you are bitten, call Poison Control at 1-800-222-1222, or 911 if symptoms are severe.
How to prevent encounters
Standard spider safety practices are sufficient for Michigan residents. While Black Widows do not live in Michigan, these practices improve overall yard safety and pest management. Wear work gloves when handling stored items in basements, attics, and garages. Shake out clothing, shoes, and bedding before putting them on or using them, which is good practice against all pests. When gardening, wear closed-toe shoes and gloves. Clear away dead wood, leaf piles, and dense brush from around your home and yard. Keep your garage, basement, and storage areas well organized and clutter-free. Store items in sealed containers or on shelves rather than on the floor. Inspect outdoor furniture before sitting on it or bringing it indoors for winter.Find more safety tips on our wildlife guides.
Where in Michigan and when
Black Widows are not found anywhere in Michigan. They do not occur in the Lower Peninsula near the Great Lakes, nor do they occur in the Upper Peninsula where winters are even colder. There are no established populations in any Michigan county. Michigan's entire climate is unsuitable for year-round Black Widow survival. Winters are too long and too cold for this spider. Even during brief summer heat waves when Michigan experiences temperatures in the 90s, these warm periods do not last long enough for Black Widows to complete their life cycle or establish populations. Fall arrives and temperatures drop back to freezing before any breeding population could develop. Black Widows thrive in the warmer climates of the southern United States.
Harmless lookalikes
The spiders found throughout Michigan are almost all harmless species native to the Great Lakes region. Cellar spiders have very long, thin legs and small bodies. They are completely harmless and help control pest insects. Wolf spiders are common in Michigan yards and gardens, with brown coloring and excellent eyesight. They hunt actively and are not venomous to humans. Jumping spiders are small, fuzzy, and remarkably cute, with excellent vision and curious behavior. Ground spiders, sheet web spiders, and orb weavers are all common and harmless. Fishing spiders live near water and are sometimes mistaken for dangerous spiders but are harmless. Cobweb spiders are found everywhere in Michigan homes and buildings. If you find any spider in Michigan, it is almost certainly one of these common harmless species.
Frequently Asked Questions
Are Black Widows deadly in Michigan? Black Widows are not found in Michigan, so this is not a real concern for state residents. Hypothetically, a Black Widow bite can be serious but is extremely rarely fatal with modern medical care. Are Black Widow bites common in Michigan? Black Widow bites do not occur in Michigan because the spider does not live here. The risk is zero for wild spiders in Michigan. What should I do if I find a spider I think might be a Black Widow? Take a clear photograph and contact your local wildlife authority, Michigan Department of Natural Resources, or a county extension office for identification.Check our wildlife databasefor safe identification of Michigan spiders.
Plan your trip
Best time to see black widow in Michigan: June, July, August
See the month-by-month sighting calendar.
Plan your black widow sighting in Michigan
80 verified black widow records have been logged in Michigan. See the GBIF records.
Where to look in Michigan
- Isle Royale National Park · Wildlife Watching, Birdwatching · Find hotels
- North Country National Scenic Trail · Wildlife Watching, Birdwatching · Find hotels
- Pictured Rocks National Lakeshore · Wildlife Watching, Birdwatching · Find hotels
- River Raisin National Battlefield Park · Wildlife Watching, Birdwatching · Find hotels
- Sleeping Bear Dunes National Lakeshore · Wildlife Watching, Birdwatching · Find hotels
- Keweenaw National Historical Park · Find hotels
Frequently asked questions
Are they in Michigan?+
Black Widows are not established anywhere in Michigan. The state's extremely cold winters, particularly in the Upper Peninsula but also throughout the Lower Peninsula, make it impossible for this heat-loving spider to survive outdoors year-round. Temperatures regularly drop well below freezing and remain there for months. Black Widows require warm conditions to complete their life cycle, and Michigan does not provide those conditions. Black Widows are found in established populations across the southern and central United States, from the mid-Atlantic states southward and westward. Michigan is well outside this range.Black Widows in Michigando not occur naturally. While an individual Black Widow might theoretically arrive in a shipment, such events are extremely rare.Michigan wildliferemains free of this spider.
How dangerous is it?+
A Black Widow bite is medically significant and deserves medical attention, though deaths are extremely rare. The venom affects the nervous system and causes muscle pain, cramping, and sweating. Symptoms typically begin within one to several hours of the bite. Most healthy adults experience painful muscle cramping that gradually improves over hours to days, particularly with medical care. Very young children, elderly people, and those with heart disease or high blood pressure face higher risk of severe reactions. Severe symptoms may include intense muscle pain, tremors, profuse sweating, nausea, and general malaise. The bite itself is often painless, and many people do not realize they have been bitten until symptoms appear.Learn about spider safety.
More wildlife in Michigan