Therefore, median pay for teachers cannot be equivalent to someone with a bachelors degree and unpaid summers off.
Furthermore, the baseline should not be calendar days but hours worked. As willcipriano's own reference #1 points out, teachers "may also work evenings and weekends to prepare lessons and grade papers."
If teachers spend their afternoons doing extracurricular activities, and evenings and weekends for grading lesson planning, giving a 55 hour week[1], while the average for someone with a bachelors degree is 40 hours[2], then the HS teacher makes ~15% less per hour than the hypothetical median bachelors degree holder. [3]
[1] https://www.scholastic.com/primarysources/pdfs/Gates2012_ful... (from 9 years ago) says teachers spend 10 hours, 40 minutes at work.
[2] https://www.thebalancecareers.com/what-is-the-average-hours-... says "Those with a bachelor’s degree or higher worked 8.0 hours per day, while those with a high school diploma worked the most on an average day: 8.2 hours."
[3] HS teacher, $62870 / (39 weeks * 55 hours/week) = $30.40/hour. Median bachelor's degree holder: $72830 / (50 weeks * 40 hours/week) = $36.42/hour. (36.42 - 30.42) / 36.42 = 16.5%.