Washington state is home to hundreds of spider species, but only a handful show up regularly in homes and gardens. The vast majority are harmless. The only spider with a medically significant bite that’s established in the state is the black widow, and even that species is largely confined to the eastern side of the Cascades. Here’s what you’re actually likely to encounter and how to tell them apart.
Hobo Spiders
The hobo spider is one of the most common spiders found throughout Washington, on both sides of the Cascades. It builds funnel-shaped webs in dark, undisturbed areas like basements, window wells, and ground-level gaps around foundations. Adults are brown with a pattern of yellowish chevron markings on a grey abdomen, though this can be hard to see without a magnifying glass.
Despite their other common name, the “aggressive house spider,” hobo spiders are neither aggressive nor dangerous. They’re shy, reluctant to bite, and try to escape when disturbed. For years, hobo spiders were listed as a venomous species of concern, but that classification has been dropped. The Washington State Department of Health no longer considers them dangerous.
Hobo spiders are frequently confused with two close relatives: the giant house spider and the barn funnel weaver. A quick way to tell them apart is to look at the legs and the underside. Hobo spiders have uniformly colored legs with no dark rings or bands. On their sternum (the plate between the legs on the underside), they have a single light stripe running down the middle. The giant house spider and barn funnel weaver, by contrast, have dark rings around their legs and pairs of light spots on the sides of the sternum. If you see spots or leg bands, it’s not a hobo.
Black Widow Spiders
Black widows are common in eastern Washington, particularly in the drier, warmer areas east of the Cascades. A few small populations exist in western Washington, but encounters on the wet side of the state are uncommon. Adult females have a body about half an inch long, glossy black coloring, and the well-known red hourglass marking on the underside of the abdomen.
Indoors, black widows favor undisturbed, cluttered spaces: basements, crawl spaces, and rarely used corners of garages. Outside, they build messy, irregular webs close to the ground in woodpiles, rock walls, and sheds. They’re not aggressive and typically bite only when accidentally pressed against skin, like when you reach into a box or put on a shoe they’ve crawled into. A bite causes intense pain and muscle cramping and warrants medical attention, but fatalities are extremely rare in healthy adults.
False Black Widows
The false black widow is common across Washington and closely resembles a female black widow. It has a similar round, bulbous abdomen and dark coloring, but it lacks the bright red hourglass. Instead, its abdomen is usually dark brown to purplish-black, sometimes with faint lighter markings. If you find what you think is a black widow in western Washington, there’s a good chance it’s actually a false black widow. Their bites can cause localized pain and mild swelling but aren’t considered medically significant.
Yellow Sac Spiders
Yellow sac spiders are found in eastern Washington and the Seattle area. They’re small, with a body about a quarter to a half inch long, and pale yellow to light green in color. Their legs span roughly an inch. Unlike web-building spiders, they’re active hunters and fast runners.
Instead of webs, they build small silk tubes or “sacs” where they rest during the day. In homes, you’ll find these sacs tucked into corners where walls meet ceilings, behind picture frames, and along windowsills. Yellow sac spiders are one of the more likely species to bite because they wander at night and can end up in bedding or clothing. The bite typically causes a sharp sting followed by redness and mild swelling, similar to a bee sting, and resolves on its own.
Cross Orb Weavers
If you’ve ever walked into a large, perfectly geometric web stretched across your porch or garden path in September, you’ve probably met a cross orb weaver. These are the classic “Charlotte’s Web” spiders, and they’re extremely common in western Washington during fall. Adults range from about 6 to 20 mm in body length, with females being much larger than males.
Their webs are made of sticky spiral silk supported by radiating spokes, and they rebuild a fresh one each day, eating the old web to recycle the silk proteins. Cross orb weavers are completely harmless to people. They sit in the center of their webs waiting for insects and have no interest in humans. Their numbers and visibility peak in autumn when they reach maturity, which is why you see so many around Halloween.
Wolf Spiders
Wolf spiders are ground hunters found throughout Washington. They don’t build webs at all. Instead, they chase down prey on foot, which is why you’ll sometimes see one sprinting across a garage floor or patio. Some species in Washington have bodies exceeding 1 cm (about half an inch), with a total leg span that can reach 2 to 3 inches, making them among the larger spiders you’ll encounter in the state.
They’re brown and hairy, which leads many people to mistake them for something more dangerous. Wolf spiders are harmless. They can bite if handled roughly, but the result is comparable to a mild bee sting. One distinctive feature: wolf spider mothers carry their egg sacs attached to their spinnerets, and after the babies hatch, dozens of tiny spiderlings ride on the mother’s back. If you see a spider covered in tiny spiders, that’s a wolf spider.
Jumping Spiders
Jumping spiders are the compact, curious-looking spiders you’ll see on sunny windowsills, fences, and exterior walls. Washington is home to several species, including some in the genus Phidippus that reach up to 15 mm in body length. They have large forward-facing eyes that give them excellent vision, and they’ll often turn to look at you if you get close, which makes them one of the few spiders people find genuinely endearing.
They hunt by stalking and pouncing on prey rather than building webs. They’re completely harmless and actually beneficial, eating mosquitoes, flies, and other pests around your home.
Brown Recluse Spiders Are Not in Washington
This is worth stating clearly because it’s one of the most common spider questions in the state: brown recluse spiders do not live in Washington. Their established range is the south-central and midwestern United States, and no resident populations have been documented in the Pacific Northwest. Many brown spiders in Washington, especially hobo spiders, giant house spiders, and wolf spiders, get misidentified as brown recluses. If someone tells you they found a brown recluse in Washington, they almost certainly found one of these other species.
Why You See More Spiders in Fall
If it seems like spiders appear out of nowhere every September and October, you’re not imagining it. Fall is mating season for most Northwest spider species. Males that normally stay hidden leave their shelters to search for females, which means they wander into living spaces, garages, and sheds more frequently. At the same time, spiders are seeking warm places to ride out the winter. As WSU entomologist Richard Zack has put it, there are hundreds of spider species in Washington, and autumn is simply when you encounter more of them because they’re on the move.
Eastern vs. Western Washington
The Cascade Range divides Washington into two very different climates, and that split shapes which spiders you’re most likely to see. Eastern Washington is drier and hotter in summer, which creates better habitat for black widows and yellow sac spiders. Western Washington’s cooler, wetter climate supports large populations of hobo spiders, giant house spiders, false black widows, and orb weavers. Some species, like hobo spiders and wolf spiders, are found statewide. But if you’re in the Seattle area and worried about black widows, your actual risk of encountering one is very low compared to someone living in Spokane, Yakima, or the Tri-Cities.