Air quality in Hiroshima, Japan today

Mr. Duck’s Air Quality Score

Good air today for Hiroshima, Japan

⚠️ This website is currently under active development. Some data may be incomplete or temporarily inaccurate. For health-critical decisions, please verify information through official government or environmental sources.

Categories follow US EPA AQI breakpoints for PM (estimate from latest valid measurements; this project does not compute EPA NowCast/24-hour AQI yet).

This friendly indicator summarizes the latest city readings. For health guidance, please see: EPA AirNow or WHO.

Air quality today

The air quality in Hiroshima today is classified as Good. The primary pollutant identified is PM2.5, with a measured concentration of 7.92 µg/m³ based on the latest data set. A total of 54 valid measurements were used to determine this assessment, and no other pollutants reached a level that would change the overall category.

Data are shown via OpenAQ. This page is informational; for health guidance, use official sources such as EPA AirNow or WHO.

Latest sensor values

PM categories follow US EPA AQI breakpoints, shown here as an estimate derived from the latest valid measurements (this project does not compute EPA NowCast/24-hour AQI yet).

What the data includes

The OpenAQ feed for Hiroshima currently contains data from twelve rows across eleven distinct monitoring stations. All of the listed pollutants are represented: carbon monoxide (CO), nitrogen oxide (NO), nitrogen dioxide (NO2), combined nitrogen oxides (NOX), particulate matter with a 1‑micron cutoff (PM1), fine particulate matter (PM2.5), sulfur dioxide (SO2), relative humidity and temperature (the latter not shown in the snapshot). The newest measurements were recorded on 2026-02-10 at either 22:00 or 23:00 UTC, so the most recent data are less than two days old for every pollutant.

Across the dataset the observed values show modest variability. For PM2.5 the median is about 7.9 µg/m³ with a range from 4.0 to 9.0 µg/m³; the 10th and 90th percentiles sit at roughly 5.0 and 8.0 µg/m³ respectively, indicating that most recent readings cluster near the middle of this span. NO concentrations are low, with a median of 0.004 ppm and values ranging from 0.001 to 0.012 ppm; the upper‑decile reaches 0.009 ppm. NO2 shows a similar pattern, median 0.012 ppm, minimum 0.008 ppm and maximum 0.017 ppm. The combined NOX metric is slightly higher, median 0.017 ppm, spanning 0.01 to 0.025 ppm.

Coverage is uneven: while PM2.5, NO, NO2, NOX and relative humidity each have twelve recent rows, CO is reported from only two stations, SO2 from four, and PM1 from a single location. This concentration of data points means that city‑wide conditions may differ in areas without nearby sensors, especially for pollutants with sparse reporting such as CO and PM1. Nonetheless, the overall freshness of the dataset suggests that the available figures reflect the current air quality situation in Hiroshima as of early February 2026.

Learn more about sources and filtering: About the data.

Trusted references: WHO (Air pollution) · US EPA AirNow · European Environment Agency (Air)

Latest sensor values (bars)

PM categories follow US EPA AQI breakpoints, shown here as an estimate derived from the latest valid measurements (this project does not compute EPA NowCast/24-hour AQI yet).

Data notes

The data shown reflect 54 valid measurements and are Updated within 3 days, with the most recent values recorded at 2026-02-10T23:00:00+00:00. This snapshot provides a current view of Hiroshima’s air quality but conditions can differ across neighborhoods and change throughout the day, so individual experiences may vary from the reported figures.

OpenAQ station rows