Open Air Chicago: Daily Aggregated Air Quality Measurements from 277 Sensors

277 non-regulatory air sensors deployed across Chicago measure fine particulate matter (PM2.5) and nitrogen dioxide (NO2), with daily means calculated for each UTC day. The project was founded by the Chicago Department of Public Health and the University of Illinois at Chicago School of Public Health, with sensors installed in Summer 2025. Data is limited to measurements that have passed automated quality control checks, and some sensors were intended to collect black carbon and weather data, though black carbon modules are offline.

Use Cases

• Analyzing daily PM2.5 pollution trends based on cloud-calibrated values.
• Studying spatial patterns of NO2 concentrations across Chicago neighborhoods.
• Correlating air quality with local weather conditions like temperature and humidity.
• Researching potential local correction factors using data from co-located federal monitoring sites.

Strengths

• Data from 277 sensor locations provides spatial coverage across Chicago.
• Includes both raw sensor readings and cloud-calibrated values for key pollutants like PM2.5 and NO2.
• Data has passed automated quality control checks as described by the provider.

Limitations

• Black carbon metrics are unavailable as the modules are offline, with data appearing blank.
• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.

Provenance

Source

City of Chicago, Chicago Department of Public Health (CDPH), University of Illinois at Chicago School of Public Health (UIC SPH).

Collection Method

Measurements from a network of 277 Clarity air sensors, with 24-hour mean aggregations calculated from raw data.

Time Range

Data collection began after sensor installation in Summer 2025; specific date range is not provided.

Freshness

Last updated 2026-03-22 04:09:17.611677; freshness should be verified.

Geography

City of Chicago, Illinois, USA.