Cinnabar Charter

Set in Petaluma, California, Cinnabar Charter is a tiny primary school, operated by Cinnabar Elementary. It instructs 156 students across grades K through 8. By comparison, California's public schools average about 465 students each, so Cinnabar Charter sits 66% smaller than that benchmark.

Across the 2 schools in Cinnabar Elementary (176 students total), Cinnabar Charter accounts for its share of the district's footprint.

In terms of who attends, Cinnabar Charter lists that the student body is overwhelmingly Hispanic (80%). The remainder comes out to 15% White, 3% multiracial. That is meaningfully more Hispanic than the county at large, where the share is closer to 30%.

On the resource side, The school reports having 9 full-time-equivalent teachers, for a student-teacher ratio near 16.4:1. The state averages around 22.3:1, so this campus is tighter than the state norm typical. Around 83% of the student body qualifies for free or reduced-price meals, a commonly cited indicator of low-income enrollment. By comparison, Sonoma County runs at roughly 51%, so the school's eligibility rate is higher than the surrounding baseline.

After controlling for student poverty, Cinnabar Charter tracks the demographic baseline. The model predicts 29.9% given the school's FRL share; actual proficiency is 19.4%.

In the area at large, census data for Sonoma County shows median household earnings sit near $104,674, about 39% of the adult population holds a bachelor's degree or above, and census figures put the poverty rate at about 5%. Across Sonoma County's 184 public schools (combined enrollment of about 63,389 students), Cinnabar Charter is one campus in the mix.

Cinnabar Elementary is the nearest neighboring public school, about 0.0 miles from this campus. 8 of the 8 nearest public schools sit inside a five-mile radius. Ranking that nearby cluster on reported proficiency puts Cinnabar Charter at 8th of 8; the average score across the group is 52.4%.

Cinnabar Charter operates from a bedroom-community location. Cinnabar Charter is a charter school, which puts it inside the public-school system but outside the standard district-managed model.

Over the past 7-year window. Cinnabar Charter's enrollment has declined 36% since 2018, when it stood at 243 (now 156). White enrollment moved from 34% to 15% across the same window. Class-load math has narrowed: from 20.3:1 in 2018 to 16.4:1 in 2025.

On this page, members of the Cinnabar Charter community share and discuss sports schedules, lunch menu changes, and school spirit week. Posting is open to anyone connected to the school.