Grayslake CHSD 127

Grayslake CHSD 127 has two listed high schools in Grayslake—Grayslake Central High School and Grayslake North High School—and both serve grades 9–12. In 2025–2026, Central scored higher than North in all nine matching subject, test and grade comparisons, and was above the state in all nine. The clearest difference was grade 9 PreACT math: Central scored 49% and North 32%, a 17-point gap; most importantly, Central led across every comparison, while North’s math results were below the state in both PreACT grades.

Central stands out overall, while North’s weakest relative results were in younger-grade math. North was above the state in seven of nine comparisons, but its grade 9 and grade 10 PreACT math scores were below the state; in grade 9, North was 10 points below the state’s 42%. The schools’ unweighted averages show the same subject pattern: together they averaged 66% in ELA and 56% in science, respectively 11 and 9 points above the matched state averages, but averaged 40% in math, just 1 point above the state. In grade 11 ACT math, the schools were nearly even: Central scored 41.1%, North 40.8%, a 0.3-point difference.

Both schools’ average scores fell by about 2 points from 2024–2025 to 2025–2026, though the subject patterns differed: Central improved in both PreACT math grades and grade 10 science, while North’s declines were especially notable in ACT science and PreACT science. SchoolDigger ranks Central 116th of 620, in the 81st percentile with four stars; North ranks 191st, in the 69th percentile with three stars. Central’s percentile fell from 85 to 81 over the period, while North’s dropped from 87 to 69. Other reported measures offer context: for 2024–2025, student–teacher ratios were 12.9 at Central and 12.5 at North; both schools report free/reduced lunch eligible figures for 2021–2022, at 12% and 17%, respectively. Chronic absenteeism was 13% at Central and 26% at North, compared with 24% statewide. These observations do not show what caused the score differences.