Seasonal Childhood Illnesses

A Year of Sick Days

When do kids get sick most? A month-by-month guide to RSV, flu, hand-foot-and-mouth, strep, pink eye, stomach bugs, and the other common childhood illnesses going around schools and daycares.

Viewing Jun

Jun activity, ranked

  • 1
    Hand-Foot-Mouth
    75%
  • 2
    Allergies
    60%
  • 3
    Lice
    45%
  • 4
    Pink Eye
    40%
  • 5
    Strep Throat
    35%
  • 6
    Common Cold
    30%
  • 7
    Stomach Bug
    25%
  • 8
    Flu
    8%
  • 9
    RSV
    8%

Going Around in Jun

  • Hand-Foot-Mouth
    Summer and early fall
    75%
  • Allergies
    Spring pollen, fall ragweed
    60%
  • Lice
    Back-to-school season
    45%

Rising into Jul

  • Hand-Foot-Mouth
    +10%

Early warning signs to watch for

Top 3 in Jun
Hand-Foot-Mouth
  • Mild fever and fussiness
  • Painful mouth sores
  • Red spots or blisters on hands and feet
  • Drooling or refusing to eat
Allergies
  • Sneezing fits
  • Itchy or watery eyes
  • Clear runny nose
  • No fever (this rules out colds)
Lice
  • Persistent scalp itching
  • Tickling feeling in hair
  • Tiny white eggs (nits) near the scalp
  • Red bumps on neck or behind ears

These are common early signs, not a diagnosis. Call your pediatrician if symptoms worsen or you are unsure.

A guide to common childhood illnesses by season

Childhood illnesses follow predictable seasonal patterns. Knowing when each one peaks, what the early symptoms look like, and which age groups are most affected helps parents prepare and respond faster. Below is a plain-language guide to nine of the most common illnesses that go around US schools, daycares, and homes.

Dec – Feb

Flu (Influenza)

Peak season

December through February, with cases rising in October and tapering by April.

Symptoms

Sudden high fever (often over 101 F), body aches, chills, dry cough, sore throat, and unusual fatigue.

Most affected

All ages, but young children, kids with asthma, and those under 5 are at higher risk of complications.

Nov – Feb

RSV (Respiratory Syncytial Virus)

Peak season

Late fall through winter, typically November to February.

Symptoms

Runny nose, congestion, wheezing or fast breathing, persistent wet cough, and poor feeding in babies.

Most affected

Infants and children under 2 are most vulnerable to severe RSV. Most older kids experience it as a bad cold.

Year-round

Common cold

Peak season

Year-round, but worse September through April when kids are indoors together.

Symptoms

Runny or stuffy nose, sneezing, mild cough, scratchy throat, and a low-grade fever.

Most affected

Preschool and elementary-age kids average 6 to 10 colds per year. Daycare-age kids can get more.

Late winter / spring

Strep throat

Peak season

The school year, with the biggest spikes in late winter and early spring.

Symptoms

Sudden sore throat without a cough, painful swallowing, fever over 100.4 F, swollen neck glands, and white patches on the tonsils.

Most affected

Kids ages 5 to 15. Strep is uncommon in children under 3.

Nov – Apr

Stomach bug

Peak season

November through April for norovirus, with year-round daycare outbreaks.

Symptoms

Sudden vomiting, watery diarrhea, stomach cramps, and a low-grade fever or chills.

Most affected

All ages, but dehydration is the biggest concern for babies and toddlers.

Jun – Sep

Hand, foot, and mouth

Peak season

Summer and early fall, June through September.

Symptoms

Mild fever and fussiness, painful mouth sores, red spots or blisters on hands and feet, drooling, or refusing to eat.

Most affected

Children under 5, especially in daycares and summer camps.

Sep – Oct

Pink eye (Conjunctivitis)

Peak season

Back-to-school months (September and October) with smaller waves through winter.

Symptoms

Red or pink eye whites, itchy or gritty feeling, watery or yellow discharge, and crusty lashes after sleep.

Most affected

Preschool and elementary kids, where it spreads quickly through shared toys and contact.

Mar – Oct

Seasonal allergies

Peak season

Tree pollen in March to May, grass pollen in May to July, ragweed in August to October.

Symptoms

Sneezing fits, itchy or watery eyes, clear runny nose, and no fever (which helps distinguish allergies from a cold).

Most affected

Kids 3 and older. Many children develop seasonal allergies in early elementary years.

Aug – Oct

Head lice

Peak season

Back-to-school weeks (August through October) and again after winter break.

Symptoms

Persistent scalp itching, a tickling feeling in the hair, tiny white eggs (nits) near the scalp, and red bumps on the neck or behind the ears.

Most affected

Elementary-age children, most often ages 3 to 11.

"Nine illnesses. Twelve months." Know what's going around, before it gets to your kid.

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