Noise maps

Interactive block-level noise heatmaps for every city in the 311info catalog with sufficient geocoded 311 noise-complaint data. Tap any block or search any address to get an A–F noise grade and a raw “complaints per week within a block” count, all computed directly from each city’s open data portal.

Current release

Data through April 2026

Refreshed with each gold-layer build · 6 cities records

How these maps are built

For each eligible city, every geocoded 311 noise complaint from the trailing 12 months is placed at its reported lat/lng and weighted by complaint type (construction and amplified music count more) and time of day (complaints filed 10pm to 7am count 2×, reflecting the disproportionate health impact of night noise). The city is tiled into a 200m grid and each cell’s density is computed via Gaussian KDE (σ = 200m). Grades are per-city percentiles: A = quietest 10%, F = loudest 10%, with B/C/D splitting the middle 80%.

Read the full methodology, citations, and caveats →

Cities with a noise map

Cities without a noise map

A city becomes eligible for a noise map when its 311 feed publishes at least 500 geocoded noise-category complaints in the trailing year. Cities below that floor are listed here. Chicago is a special case: its 311 system publishes a large volume of noise complaints, but 100% are aircraft-noise filings with no reported coordinates, so there’s nothing to pin on a map. We may add a ZIP-level choropleth fallback for cases like this in a future update.

All noise scores are per-city percentiles. An A in one city and an A in another both mean “quietest 10% of complaint-covered locations in that city” — not “equally quiet in absolute terms.” The raw complaints per week within a blockcount on each map is the direct, unweighted number you can verify against the city’s open data feed. Full methodology →