Ticks in South Dakota

Ticks are active in South Dakota whenever the ground is not frozen, led by the Lyme-carrying deer tick. TickZone scores all 310 South Dakota towns every morning, so risk stays local: pick your town for today's number, a 7-day outlook, and what's driving it.

Tick season in South Dakota

Tick season in South Dakota runs whenever the ground is not frozen, roughly March through November, with two peaks. Nymph deer ticks, the poppy-seed-sized stage that causes most Lyme cases, peak from late May through July. Adult deer ticks make a second push in October and November, and on any winter day above about 40 F they can quest again. American dog ticks are busiest from April through July.

Generalized for the Northeast and Upper Midwest Lyme belt.
Life stageJFMAMJJASOND
Deer tick nymphs
Deer tick adults
American dog tick
Peak Active
Generalized for the Northeast and Upper Midwest Lyme belt. Activity windows by life stage from TickEncounter (Univ. of Rhode Island) and the Northeast Regional Center for Excellence in Vector-Borne Diseases. Any warm spell can wake ticks earlier than the calendar suggests.

Those are averages, and any single week can run hotter or colder than the calendar suggests. The daily score on every town page folds the season, the weather, and local habitat into one number each morning, so it is the safer way to time yard work, hikes, and pet prevention.

Highest-risk towns in South Dakota (2026)

South Dakota's highest-risk towns are spread across several counties, led by Lawrence. The top 10 towns run 0 to 89 percent forest, ranked at peak season so the list stays stable.

  1. 1Wetonka McPherson CountyModerate at peak
  2. 2Keystone Pennington CountyModerate at peak
  3. 3Central City Lawrence CountyModerate at peak
  4. 4Deadwood Lawrence CountyModerate at peak
  5. 5Brant Lake Lake CountyModerate at peak
  6. 6Lead Lawrence CountyModerate at peak
  7. 7Strandburg Grant CountyModerate at peak
  8. 8Astoria Deuel CountyLow at peak
  9. 9Hill City Pennington CountyLow at peak
  10. 10Fairview Lincoln CountyLow at peak

See the riskiest towns in every state →

All South Dakota towns, by county

Aurora County · 3 towns

Beadle County · 8 towns

Bennett County · 1 towns

Bon Homme County · 5 towns

Brookings County · 8 towns

Brown County · 10 towns

Brule County · 3 towns

Butte County · 4 towns

Campbell County · 4 towns

Charles Mix County · 7 towns

Clark County · 7 towns

Clay County · 2 towns

Codington County · 6 towns

Corson County · 3 towns

Custer County · 5 towns

Davison County · 3 towns

Day County · 8 towns

Deuel County · 7 towns

Dewey County · 3 towns

Douglas County · 3 towns

Edmunds County · 4 towns

Fall River County · 3 towns

Faulk County · 7 towns

Grant County · 9 towns

Gregory County · 6 towns

Haakon County · 2 towns

Hamlin County · 6 towns

Hand County · 3 towns

Hanson County · 4 towns

Harding County · 2 towns

Hughes County · 3 towns

Hutchinson County · 6 towns

Hyde County · 1 towns

Jackson County · 4 towns

Jerauld County · 3 towns

Jones County · 2 towns

Kingsbury County · 9 towns

Lake County · 5 towns

Lawrence County · 5 towns

Lincoln County · 7 towns

Lyman County · 4 towns

Marshall County · 5 towns

McCook County · 5 towns

McPherson County · 5 towns

Meade County · 4 towns

Mellette County · 2 towns

Miner County · 4 towns

Minnehaha County · 11 towns

Moody County · 5 towns

Oglala Lakota County · 1 towns

Pennington County · 8 towns

Perkins County · 2 towns

Potter County · 4 towns

Roberts County · 10 towns

Sanborn County · 3 towns

Spink County · 10 towns

Stanley County · 1 towns

Sully County · 2 towns

Todd County · 2 towns

Tripp County · 3 towns

Turner County · 10 towns

Union County · 5 towns

Walworth County · 6 towns

Yankton County · 6 towns

Ziebach County · 1 towns

South Dakota tick questions

Are there ticks in South Dakota?
Yes. South Dakota has ticks in every county, led by the deer tick (blacklegged tick) that spreads Lyme disease, along with the American dog tick. They are active whenever the ground is not frozen, and today 6 of the state's 310 towns are at moderate or high tick risk on TickZone's daily score.
What types of ticks live in South Dakota?
South Dakota has the deer tick (blacklegged tick), which carries Lyme disease; the American dog tick; and the lone star tick, which is not established in the state and causes alpha-gal syndrome. See the South Dakota tick identification chart for photos and how to tell them apart.
When does tick season start and end in South Dakota?
In South Dakota, ticks are active whenever the ground is not frozen, roughly March through November. Nymph deer ticks peak in June and July and cause most Lyme cases, and adult ticks have a second peak in the fall. On any winter day above freezing, adult ticks can still bite.
When is flea and tick season?
Flea and tick season generally runs from early spring through late fall, peaking in the warm summer months. In South Dakota, start prevention for pets and people in March and keep it up through November, since ticks can bite on any mild day.
Which tick carries Lyme disease in South Dakota?
The deer tick, also called the blacklegged tick, is the tick that spreads Lyme disease in South Dakota. The American dog tick and lone star tick do not carry Lyme.