An increase in black widow sightings along sidewalks and retaining walls in Lehi is being linked to a record-warm winter and the presence of ideal habitats within residential streetscapes. According to local reports, the issue involves a distinction between public infrastructure and private property, as municipal rules place pest control responsibilities on property owners when webs are found on private walls adjacent to public paths.
The National Weather Service in Salt Lake City reported that the 2025–26 winter was the warmest since record-keeping began in 1874. The meteorological winter averaged 40.7 degrees, which is 7.6 degrees above normal. Pest specialists suggest this exceptional warmth may have allowed western black widows to begin their season earlier and produce more egg sacs.
Utah State University Extension identifies the species as the western black widow, which features a shiny black body and a red hourglass under the abdomen. These spiders prefer dark, undisturbed areas such as building foundations, wood piles, and retaining walls.
While the black widow is Utah's major spider of medical concern, experts from USU Extension and the Utah Plant Pest Diagnostic Laboratory note that brown recluse spiders do not occur in Utah. Officials recommend integrated pest management strategies, such as sealing cracks, vacuuming webs, and reducing outdoor clutter, rather than relying on pesticides.
In Lehi, the Streets Department maintains sidewalks, but resident rules indicate that snow clearing and the management of landscaping or personal property in the right-of-way are the responsibility of the property owner. The city does not operate a pest-mitigation program for spiders located on private walls.
Medical professionals emphasize that while black widow bites should be taken seriously, the spiders are generally docile and more likely to flee than bite unless disturbed. The Utah Poison Control Center notes that most envenomation cases are managed without emergency room visits, and death from such bites has not occurred in their modern clinical records.
Residents concerned about public infrastructure can use Lehi's iWorQ Report an Issue portal, while those dealing with private property issues should focus on habitat reduction. Anyone experiencing symptoms of a bite is directed to contact the Utah Poison Control Center at 1-800-222-1222.
