Microproduct data guideintermediate

EPA AirData Daily Summaries

Quality-assured daily ambient air-monitor measurements for building historical pollution, compliance-context, and station comparison tools.

Start the guide Open official source

At a glance

Difficulty
Intermediate — some data preparation helps
Size
Medium · 0.001–1 GB
Formats
CSV, ZIP
Access
Download
API key
Not required
Provider
U.S. Environmental Protection Agency
Updates
Daily
Data terms
U.S. Government public data / federal copyright guidance

From source to product signal

Test a product idea in four steps

AirData publishes daily summaries from EPA's regulatory Air Quality System. Start with one pollutant, one year, and one state. Monitor coverage and methods change, recent values may not be certified, and these historical regulatory records differ from preliminary operational AirNow data.

1

Check the setup

  • Python 3.10 or newer
  • A notebook environment such as Jupyter or Google Colab
  • Enough memory for one annual pollutant ZIP file
2

Access the data

  1. 1.Open AirData and select one daily pollutant file and year.
  2. 2.Read the file-format documentation and retain site, parameter, standard, and method identifiers.
  3. 3.Filter immediately to one state and record the file update date.
Open official source
3

Run the Python example

Install the packages, then run the notebook cell.

python -m pip install pandas

import pandas as pd

url = "https://aqs.epa.gov/aqsweb/airdata/daily_88101_2025.zip"
daily = pd.read_csv(url, dtype={"State Code": "string", "County Code": "string", "Site Num": "string"})
california = daily[daily["State Code"] == "06"].copy()
california["Date Local"] = pd.to_datetime(california["Date Local"])
print(california[["Date Local", "County Code", "Site Num", "Arithmetic Mean", "Units of Measure"]].head(20))
4

Test a useful signal

Compare daily PM2.5 summaries within one state

Review 2025 daily PM2.5 summaries for California monitoring sites.

  1. 01Filter the annual file to California and construct a stable site identifier from state, county, and site codes.
  2. 02Summarize completeness and arithmetic means by site without mixing units or standards.
  3. 03Explain how monitor placement, methods, completeness, certification timing, and AirNow differences limit conclusions.

Dataset details

U.S. Environmental Protection Agency is a government source. Last verified 2026-08-13. Temporal coverage: annual pollutant files from 1980-present with parameter-specific coverage.

Theme

Environment & Hazards

Domains

Air QualityEnvironmental Health

Data types

Time SeriesTabular

Tasks

Trend AnalysisMonitoringStation Comparison

Geography

United States

Formats

CSVZIP

Provider

U.S. Environmental Protection Agency

Data terms

U.S. Government public data / federal copyright guidance