Average
#3067 of 4,739 schools in NY
William Sidney Mount Elementary School
Elementary School · THREE VILLAGE CENTRAL SCHOOL DISTRICT
PO BOX 9050, East Setauket, NY 11733
Enrollment
514
Student-Teacher
13.9:1
Score
5.8
Grades
Pre-K – 6th
Enrollment
514
Student-Teacher
13.9:1
Score
5.8
Grades
Pre-K – 6th
Updated
2022-23
Updated 2022-23
How this school compares
In East Setauket
#8 of 8
public schools
New York elementary schools
#1,678 of 2,549
In district
#8 of 8
THREE VILLAGE CENTRAL SCHOOL DISTRICT
Academic performance
7.2 / 10
Strong
About William Sidney Mount Elementary School
William Sidney Mount Elementary School serves 514 students from prekindergarten through sixth grade in East Setauket, providing a solid educational foundation with a student-teacher ratio of 13.9:1 across 37 full-time equivalent teachers. The school demonstrates strong academic performance, earning a MySchoolScout rating of 7.0 out of 10 and ranking in the 78th percentile among New York elementary schools at #1046 out of 4758 statewide. Students at William Sidney Mount show commendable academic achievement, with 68% scoring proficient or above in English Language Arts and Reading, while 63% reach proficiency in Mathematics.
These results reflect the school's commitment to academic excellence and student development across all grade levels. The school draws from a well-educated and affluent community where 63% of residents hold bachelor's degrees or higher, and the median household income reaches $170,074. With a low poverty rate of just 4.3% and median home values of $629,400, the surrounding ZIP code of 11733 represents a stable, educationally-focused environment that strongly supports student learning.
William Sidney Mount Elementary School operates within East Setauket's large suburban setting in Suffolk County, offering families a blend of academic quality and community stability that characterizes this well-established Long Island neighborhood.
Score Breakdown
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William Sidney Mount Elementary School — Students at William Sidney Mount Elementary School score 67% proficient, which is below what's typical for similar communities (expected: 69%).
Equity & Diversity
Shown separately, not included in overall scoreFree/Reduced Lunch
20%
Students qualifying for federal meal assistance
Test Scores NY NYSED (2020-21)
Based on 12 test records from NY state assessments. About our data
Proficiency Trend
↓ DecliningAverage proficiency (% at or above grade level) across Math & ELA over time.
* COVID-affected year — test participation was uneven nationwide. This data is weighted at 50% in the Growth score calculation.
Source: EdFacts (NCES) and state assessment data. Growth score: 4.9/10.
How William Sidney Mount Elementary School Compares
See how William Sidney Mount Elementary School performs across key quality dimensions compared to state benchmarks.
Funding & Resources
Performance Trends
Math proficiency has declined from 77% (2019) to 67% (2021). Reading/ELA proficiency has remained stable from 67% (2019) to 67% (2021).
Location
PO BOX 9050, East Setauket, NY 11733
Nearby Alternatives
Families considering William Sidney Mount Elementary School may also want to explore other elementary schools in the area. MILLS POND ELEMENTARY SCHOOL (rated 9.1/10, 1.3 miles away, in nearby St. James), which scores notably higher. Another option is DOGWOOD ELEMENTARY SCHOOL (rated 8.6/10, 3.2 miles away, in nearby Smithtown), which scores notably higher. Additionally, WENONAH SCHOOL (rated 8.2/10, 3.2 miles away, in nearby Lake Grove), which scores notably higher. For more schools in East Setauket, see our East Setauket schools guide .
Nearby Schools
20 within 3.2 mi| School | Distance | Rating |
|---|---|---|
| MILLS POND ELEMENTARY SCHOOL St. James | 1.3 mi | 9.1 |
| HARBOR COUNTRY DAY SCHOOL Saint James | 1.1 mi | 8.1 |
| ROBERT CUSHMAN MURPHY JUNIOR HIGH SCHOOL East Setauket | 1.2 mi | 6.1 |
| SAINT JAMES ELEMENTARY SCHOOL Saint James | 1.4 mi | 7.8 |
| THE STONY BROOK SCHOOL Stony Brook | 2.0 mi | 6.7 |
| NORTH SHORE MONTESSORI SCHOOL Stony Brook | 2.0 mi | — |
| SS PHILIP & JAMES SCHOOL Saint James | 1.8 mi | 5.9 |
| NASSAKEAG ELEMENTARY SCHOOL East Setauket | 2.0 mi | 7.2 |
| EUGENE AUER MEMORIAL SCHOOL Lake Grove | 2.3 mi | 7.6 |
| SMITHTOWN HIGH SCHOOL EAST Saint James | 2.2 mi | 8.0 |
| MINNESAUKE ELEMENTARY SCHOOL East Setauket | 2.6 mi | 7.7 |
| WENONAH SCHOOL Lake Grove | 3.2 mi | 8.2 |
| NESAQUAKE MIDDLE SCHOOL Saint James | 2.6 mi | 5.4 |
| PAUL J GELINAS JUNIOR HIGH SCHOOL East Setauket | 3.2 mi | 7.4 |
| OXHEAD ROAD SCHOOL Centereach | 2.7 mi | 6.1 |
| DAWNWOOD MIDDLE SCHOOL Centereach | 2.8 mi | 4.6 |
| CENTEREACH HIGH SCHOOL Centereach | 2.9 mi | 6.7 |
| THE KNOX SCHOOL Saint James | 2.9 mi | 8.2 |
| TACKAN ELEMENTARY SCHOOL Nesconset | 3.7 mi | 8.2 |
| DOGWOOD ELEMENTARY SCHOOL Smithtown | 3.2 mi | 8.6 |
Neighborhood Census ACS (2019-2023)
Census data for ZIP 11733 (ACS 2019-2023 5-Year Estimates) · Data sources
Median Income
$174,931
Median Home Value
$653,100
Median Rent
$2,386/mo
Population
17,403
College Educated
62.9%
Homeownership
84.8%
Avg Commute
29.9 min
Poverty Rate
4.6%
Median Age
44.7
Community Profile
The community surrounding William Sidney Mount Elementary School has a median household income of $174,931. It is a well-educated community where 63% of adults hold a bachelor's degree or higher. The median home value in the area is $653,100, with a median rent of $2,386/month. The local poverty rate of 4.6% is relatively low. The average commute for residents is 30 minutes. Source: U.S. Census ACS 2022 5-Year Estimates.
Similar Schools
Schools in the same state with comparable level, size, and ratings
| School | Rating |
|---|---|
| BARACK OBAMA ELEMENTARY SCHOOL Hempstead, NY | 5.8 |
| BARRINGER ROAD ELEMENTARY SCHOOL Ilion, NY | 5.8 |
| BELLAMY ELEMENTARY SCHOOL Rome, NY | 5.8 |
| CHENANGO FORKS ELEMENTARY SCHOOL Binghamton, NY | 5.8 |
| CORINTH ELEMENTARY SCHOOL Corinth, NY | 5.8 |
| DAVISON AVENUE INTERMEDIATE SCHOOL Lynbrook, NY | 5.8 |
Frequently Asked Questions
Common questions about William Sidney Mount Elementary School
What grades does William Sidney Mount Elementary School serve?
William Sidney Mount Elementary School serves students in grades Pre-K through 6th.
How many students attend William Sidney Mount Elementary School?
William Sidney Mount Elementary School has an enrollment of approximately 514 students.
What is the student-teacher ratio at William Sidney Mount Elementary School?
The student-teacher ratio at William Sidney Mount Elementary School is 13.9:1. A lower ratio generally means more individual attention per student. The national average is approximately 16:1 for public schools.
How does William Sidney Mount Elementary School rank in NY?
William Sidney Mount Elementary School is ranked #3067 out of 4,739 schools in NY.
What is William Sidney Mount Elementary School's MySchoolScout rating?
William Sidney Mount Elementary School has a composite rating of 5.8 out of 10 on MySchoolScout. This score combines academic performance, student growth, and school environment into a single score. Equity data is shown separately for context.
What are the test scores at William Sidney Mount Elementary School?
Based on the most recent state assessment data, William Sidney Mount Elementary School has 66.0% math proficiency and 67.3% reading/ELA proficiency.
Is William Sidney Mount Elementary School a charter school?
No, William Sidney Mount Elementary School is not a charter school. It is a traditional public school operated by the local school district.
Is William Sidney Mount Elementary School a Title I school?
No, William Sidney Mount Elementary School is not currently a Title I school.
What does the Free & Reduced Lunch percentage mean for William Sidney Mount Elementary School?
20.0% of students at William Sidney Mount Elementary School qualify for free or reduced-price lunch. This is a commonly used indicator of economic need and provides important context when interpreting test scores.
Neighborhood Context
- County Safety
- Low (3/100K)
FBI UCR 2024. County-level only. Data >1 year old.
Quick Facts NCES CCD (SY 2022-23)
- Grades
- Pre-K – 6th
- Enrollment
- 514
- Student-Teacher Ratio
- 13.9:1
- Teachers (FTE)
- 37
- Free/Reduced Lunch
- 20.0%
- Type
- regular
- Setting
- Large Suburb
- County
- Suffolk County
- Phone
- (631) 730-4300
- Data Year
- 2023–2024
Resources & Links
District
THREE VILLAGE CENTRAL SCHOOL DISTRICT- District Enrollment
- 5,686
- Schools in District
- 8
- Per-Pupil Spending
- $36,894
- District Rank
- #8 of 8
How We Rate Schools
Every school receives a composite score from 1 to 10 based on four pillars: Academic Performance (50%), Student Growth (20%), Equity (15%), and Learning Environment (15%). Scores are built from publicly available data including standardized test results, enrollment figures, and school climate indicators.
Read our full methodologyRelated reading
- Best Public Schools in New York 2026: Top Districts from NYC to the Suburbsbest schools
- Best Schools in New York, NY — 2026 Rankingsbest schools
- Best States for Public Schools in 2026: A Complete Rankingdata insights
- Charter Schools vs Public Schools: What the Data Actually Shows (2026)school choice
- Student-Teacher Ratio by State: Complete 2026 Rankingsdata insights
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