# O2Quality

> Real-time and forecasted air quality index and pollutant levels. (iPhone/iPad app by Tomohiko Shimizu.)

- Source: https://appshunter.io/ios/app/o2quality/id1570058656 (this page in markdown: same URL + `.md`)
- Developer: [Tomohiko Shimizu](https://appshunter.io/developer/436129129)
- Category: Weather, Lifestyle
- Price: Free
- Age rating: 4+
- Requires: iOS 26.0 · 6 MB
- Languages: American English, Japanese
- Released: 2021-06-03
- Data updated: 2026-08-24
- Monetization: free
- User reviews in markdown: https://appshunter.io/ios/app/o2quality/id1570058656/reviews.md

## What is O2Quality?

O2Qualityは、いまいる場所の大気汚染の状況を、いまいる場所の大気汚染の状況を、米国大気質指数と欧州大気質指数が定める空気質指数(AQI)と、お近くにある観測地点の一酸化炭素など6種類の予報をお伝えするアプリです。

※ O2QualityはWeather data by Open-Meteo.comのデータを利用しています。All data is provided as is without any warranty.
※ 日本国内では、いまいる場所の最寄りに大気汚染を測定する装置が必要十分な数だけ設置されていないエリアがあると考えられます。

[ 空気質指数(AQI)を分かりやすくにお伝えします ]
米国大気質指数と欧州大気質指数が定める10段階の空気質指数(AQI)を、危険度の段階を表す数字と概要、そして危険度を表す色でお伝えします。

[ 6種類の汚染物質の指数をお伝えします ]
一酸化炭素(Carbon Monoxide)、オゾン(Ozone)、二酸化窒素(Nitrogen dioxide)、二酸化硫黄(Sulphur dioxide)、PM2.5、PM10といった汚染物質を対象に、およそ5日間の予報値をお伝えします。

[ 6種類の汚染物質の濃度をお伝えします ]
一酸化炭素(Carbon Monoxide)、オゾン(Ozone)、二酸化窒素(Nitrogen dioxide)、二酸化硫黄(Sulphur dioxide)、PM2.5、PM10といった汚染物質を対象に、およそ5日間の予報値をお伝えします。

## Key features

- Real-time AQI reporting
- US and European AQI standards
- Forecasts for 6 pollutants
- 5-day pollutant forecasts
- Color-coded risk levels
- Pollutant concentration data

## Recent user reviews (1 of 1)

All indexed reviews: https://appshunter.io/ios/app/o2quality/id1570058656/reviews.md

### 4/5 — なかなか良いです。

*2023-06-25*

米国と欧州の基準で地元の大気指数の
履歴を見られるので、空気にこだわる
人に良いと思います。

## Frequently asked questions about O2Quality

### What is O2Quality?

O2Quality provides real-time air quality information based on US and European Air Quality Index (AQI) standards. It forecasts pollutant levels for up to five days, including carbon monoxide, ozone, nitrogen dioxide, sulfur dioxide, PM2.5, and PM10.

### What data sources does O2Quality use?

O2Quality utilizes weather data from Open-Meteo.com. All data is provided as is without any warranty.

### Does O2Quality have ads?

No, O2Quality does not contain advertisements.

### What pollutants does O2Quality track?

O2Quality tracks six types of pollutants: Carbon Monoxide, Ozone, Nitrogen dioxide, Sulphur dioxide, PM2.5, and PM10.

### What is the AQI scale used by O2Quality?

O2Quality uses a 10-level Air Quality Index (AQI) defined by US and European standards, presented with numerical risk levels, summaries, and color-coded indicators.

### What devices is O2Quality available on?

O2Quality is available on Mac, iPhone, and iPad.

### How often is O2Quality updated?

The latest version of O2Quality is 2.5, and it was last updated on September 19, 2025.

### Is O2Quality suitable for children?

O2Quality has an age rating of 4+, making it suitable for children.

## Version history (last 5 releases)

### 2.5 — 2025-09-19

iOS26のLiquid Glassに準拠したデザインとアイコンに対応。
アプリ全体のUIデザインを全面的に再構築。
その他細かな改良、バグフィックスを実施。

### 2.4 — 2024-09-16

タブバーを最新仕様に最適化。
ホーム画面のアイコンをダークまたは淡色にカスタマイズできるよう対応。
位置情報サービスの利用を最新の方式に移行。
最新のローカライズ方式に移行。
その他細かな改良、バグフィックスを実施。

### 2.3 — 2024-05-11

最新のプログラミング文法ならびにプライバシー定義に準拠
その他細かな改良、バグフィックスを実施。

### 2.2 — 2023-08-20

UI画面周りの機能を最適化。
その他細かな改良、バグフィックスを実施。

### 2.1 — 2023-05-15

欧州大気質指数の評価カラーを正しい内容に修正。
パネル設定画面が正常に表示できない場合がある不具合を修正。
その他細かな改良、バグフィックスを実施。

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## More apps by Tomohiko Shimizu

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- [EveryYear](https://appshunter.io/ios/app/everyyear/id593355952)

All apps by Tomohiko Shimizu: https://appshunter.io/developer/436129129

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-24.*