California · West

Tick risk in San Diego County, California

San Diego County covers 51 towns and carries the 5th-highest tick-borne-disease baseline of California's 57 counties, with a Lyme rate of 0 cases per 100,000 people a year (0th of 0 counties in the West). Pick your town below for today's score, a 7-day outlook, and what's driving it.

Highest and lowest tick risk in San Diego County

Peak-season modeled risk. Tick risk is local, even within one county.

At the summer peak, tick risk across San Diego County runs from Julian (moderate) at the high end to Borrego Springs (low) at the low end. The difference is habitat: forest cover across the county ranges from 2% to 59%, and more forest and woodland edge means more places ticks can quest for a host.

JulianModerate risk
DescansoModerate risk
Pine ValleyModerate risk
Rancho Santa FeModerate risk
Harmony GroveModerate risk

Tick species in San Diego County

CDC county surveillance (established or reported)

Deer tickReported
American dog tickReported
Lone star tickNot established
Gulf Coast tickNot established

Reported in this county for the deer tick, the main Lyme carrier. “Not established” means no CDC surveillance record for San Diego County, not that a town is tick free. Source: CDC tick surveillance (ArboNET Tick Module), 2025.

Diseases found in local ticks

No CDC tick-testing records for San Diego County. That is a surveillance gap, not a sign these diseases are absent. Lyme and other tickborne illnesses occur across the region.

Tick control in San Diego County, CA

Professional tick control across San Diego County usually means a barrier treatment along the lawn edge, leaf litter, stone walls, and shady borders where ticks wait for a host, applied two to four times a season by a licensed pest control company. It is the single most effective way to cut tick numbers in the part of the yard your family actually uses, and it matters most in San Diego County's more wooded towns.

How much does tick control cost in San Diego County?

Most San Diego County homeowners pay about $100 to $200 per visit for professional tick spraying, or roughly $350 to $600 for a full season of barrier treatments, depending on lot size and how wooded the property is. Quotes are free, so it costs nothing to get a real number for your yard.

Get a free tick control quote

From a vetted local tick exterminator serving San Diego County. No cost, no obligation.

Common questions about ticks in San Diego County

Which towns in San Diego County have the highest tick risk?

At the summer peak, Julian carries the highest modeled tick risk in San Diego County, followed by Descanso, Pine Valley, Rancho Santa Fe, Harmony Grove. Risk tracks how wooded a town is: forest cover across San Diego County ranges from 2% to 59%, and the more forest and woodland edge a town has, the more habitat ticks have to quest from. Borrego Springs sits at the low end. Every town has its own daily score, so check the one nearest you.

What ticks live in San Diego County?

CDC county surveillance does not yet list an established tick species for San Diego County, but that reflects a surveillance gap, not absence. The blacklegged (deer) tick, the main Lyme carrier, is found across the west. Take the usual precautions after time outdoors.

Is Lyme disease common in San Diego County?

San Diego County reports about 0 Lyme cases per 100,000 people a year (U.S. CDC), the 5th-highest of California's 57 counties. Lyme is the dominant blacklegged-tick disease, so TickZone uses this county rate as the disease baseline behind every town's score.