Sewickley Hills Borough, PA

Nymphs are questing, the highest-risk stage for people. Nymphal deer ticks peak in late spring and summer. They're the size of a poppy seed, easy to miss, and cause most Lyme transmission.

Sewickley Hills Borough is 97% natural land cover (91% forest, plus open and brushy areas) across its 2.47 sq mi, home to about 688 people. That makes it the 12th-most wooded of the 130 towns in Allegheny County. Deer ticks live in wooded areas, along trail edges, and in tall grass — the more of that a town has, the more places ticks can quest.

Allegheny County reports about 69 Lyme cases per 100,000 people a year, the 171st-highest of 210 Northeast counties. That county-level disease pressure, combined with Sewickley Hills Borough's local habitat, sets how high its daily score can climb when the weather and season allow.

Yes. Nymphs are questing, the highest-risk stage for people. In Sewickley Hills Borough, today's risk reads moderate (45/100). Ticks are active. Use repellent, stick to trails, and do a tick check when you come inside.