Summary:
Zip code 98188 has one listed middle school, Chinook Middle School, serving grades 6–8 in SeaTac through the Highline School District. The school enrolls 620 students and serves an area where 72.9% of students qualify for free or reduced-price lunch, an important consideration when evaluating its academic results and student support needs.
Chinook Middle School has both strengths and areas needing attention. Science is the school’s strongest subject relative to the district: 33.33% of students reached proficiency in 2025–2026, slightly above the district’s 32.82%. Science also improved from the previous year. Eighth grade was the strongest-performing grade in the available results, with 32.54% proficiency in English Language Arts and 20.59% in Math—both slightly above district results. Sixth-grade ELA performance was nearly equal to the district, while seventh grade had the largest gaps, especially in Math.
Math is the clearest academic challenge at Chinook Middle School. Schoolwide Math proficiency was 15.67%, compared with 24.30% in the district and 43.11% statewide. ELA proficiency was 29.44%, below the district’s 34.68% and the state’s 52.81%. The school ranked in approximately the 10th to 13th percentile statewide during the past three years, including the 10th percentile in 2025–2026. Parents may want to ask about seventh-grade Math support, intervention programs, and how the school is building on comparatively stronger eighth-grade and Science results. The school reports a 17.3:1 student-teacher ratio and $21,795 in spending per student.
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