When is lice season in Portland? Our data says summer.
Most parents expect lice to show up in September, with the first notes home from school. Four years of our own appointments across the Portland metro tell a different story: the busiest month is July, and lice stay busy from May all the way through November.
Each bar is that month's lice appointments compared with an average month (100). Portland metro, 2022–2025.
- July is the busiest month of the year, about 40% above an average month.
- Lice season is long. Every month from May through November runs above average. That's seven months in a row.
- Back-to-school is busy, but it isn't the peak. September runs about 12% above average, below both July and August.
- January through April is the quiet stretch, 20–40% below an average month.
Why summer? Lice spread almost entirely through direct head-to-head contact. Summer is camps, sleepovers, sports, road trips and cousins sharing beds, with nobody at school checking heads. Many cases that turn up in August and September were probably picked up weeks earlier. We can't prove that from appointment data alone, but it matches what families tell us when we ask where their child has been.
- Check before and after camp. A quick check before your child leaves keeps you from bringing lice to camp. A check when they get home catches anything they picked up.
- Check after sleepovers. Many parents spot lice after a weekend, and Monday is one of our busiest days.
- Check weekly from May to November if your kids are in camps, sports or childcare. A wet check with conditioner and a metal lice comb takes about 15 minutes.
- Don't wait for a note from school. Summer cases have no school nurse to catch them, so the first warning is usually an itchy head weeks later.
We counted every lice treatment and lice-check appointment Lice Charmers booked in the Portland metro, at our SE Portland and Beaverton clinics and in families' homes, from January 2022 through December 2025. Our business grew each year, so each month is shown against that year's own monthly average, and the four years are then averaged. 2020 and 2021 are left out because the pandemic closed schools and camps.
This shows when Portland families came to a professional for help. It isn't a count of how many people in Portland have lice, and families who treat at home don't appear in it.
School nurses, PTAs, camps, reporters and parenting sites are welcome to republish the chart and these numbers. Please credit “Lice Charmers” and link to this page. For interviews, call 971-771-2960.