Glendale Union High School District

Glendale Union High School District has 11 high schools serving grades 9–12 in the Glendale area: nine conventional schools and two online schools. Across the schools, average proficiency is about 37% in ELA, 32% in math and 17% in 11th-grade science, compared with state figures of 41%, 33% and 19%, respectively. The averages conceal large differences among individual schools, making school-to-school variation the most important finding for families comparing options.

Sunnyslope High School leads in ELA (56%) and math (48%), each 15 percentage points above the state figure; Thunderbird High School leads in science (27%), 8 points above the state. At the lower end, the Glendale Union High School District Online Learning Academy has the lowest reported ELA result (10%); its math result is suppressed. Among conventional schools, Cortez High School has the lowest ELA result (23%), while Glendale High School is lowest in math (19%) and science (9%). The ELA results span 10% to 56%, and reported math results span 19% to 48%. Completion figures also distinguish the online schools: their graduation rates are 41% and 38%, compared with a 93% average for conventional schools and 80% statewide.

SchoolDigger’s statewide percentile rankings improved for seven of the nine conventional schools from 2023–24 to 2025–26; their average rose from the 44th to the 52nd percentile. Moon Valley High School had the largest gain among them, rising 19 points, while Thunderbird fell 3 points and Cortez was unchanged. Results also do not follow a simple student–teacher-ratio pattern: Greenway High School and Cortez have similar ratios (21.1 and 21.6), yet Greenway is 26 points higher in ELA and 14 higher in math; Sunnyslope has the highest conventional-school ratio (23.7) and the strongest ELA and math results. SchoolDigger rankings are relative measures rather than test-score changes, and free/reduced-lunch information is not reported.