Air quality index for Perth, as of (Australia/Perth). Values update hourly — see this page for the current reading and hourly forecast. Today's peak: AQI 60 at 01:00 local time.

airindex·today

Air Quality in Perth

Perth is now at AQI 56 (moderate), below today's high of AQI 60 in the same band around 01:00. Today's main contributor is fine particulate matter (PM₂.₅), at 11 µg/m³. Little changes hour to hour: today's values stay between AQI 55 and AQI 60.

Now, Oct 17at 19:00
56Moderate
Good0–50
Moderate51–100
Sensitive groups101–150
Unhealthy151–200
Very unhealthy201–300
Hazardous301+

By pollutant

  • PM₂.₅ fine particles · sets the index nowAQI 56
  • O₃ ozoneAQI 29
  • PM₁₀ coarse particlesAQI 18
  • NO₂ nitrogen dioxideAQI 5
  • SO₂ sulfur dioxideAQI 2
  • CO carbon monoxideAQI 1
Unusually sensitive people should consider reducing prolonged or intense outdoor activity

Modeled forecast data. AQI values come from atmospheric models (CAMS via Open-Meteo), not local monitoring stations. Readings can differ from ground-level conditions — for exact street-level values, consult an official air quality station near you. The forecast is calculated for a grid square, roughly 11 km across Europe and 45 km elsewhere, and air quality can vary within one square.

The next 48 hours

Hourly air quality index for Perth · Local time (GMT+8)

Today, Oct 17
Tomorrow, Oct 18
50
Peak 60 · 01:00
Peak 54 · 00:00
0:00
6:00
12:00
18:00
0:00
6:00
12:00
18:00

Good ≤ 50

Now
Show hourly data table
TimeAQIPM₂.₅µg/m³PM₁₀µg/m³O₃µg/m³NO₂µg/m³SO₂µg/m³COmg/m³°C
Today
00:005921270.0417.20.1915°
01:006021271.0417.50.1914°
02:006021271.0417.50.1813°
03:006020260.0407.00.1812°
04:006020260.0396.30.1712°
05:006020261.0365.70.1713°
06:006021245.0305.60.1713°
07:0059202110225.60.1814°
08:0059131830136.60.1217°
09:00591117399.65.40.1119°
10:00599.114505.63.90.0921°
11:00589.515602.62.60.0822°
12:00589.715651.42.00.0823°
13:00589.615681.21.80.0824°
14:00579.515691.31.70.0824°
15:00579.615681.11.60.0823°
16:00569.715651.21.70.0822°
17:00569.815602.41.90.0822°
18:00561016516.02.30.0921°
19:0056111741112.90.1020°
20:0055131933143.20.1119°
21:0055132031153.20.1118°
22:0055131831143.10.1118°
23:0055111733132.80.1117°
Tomorrow
00:0054101535102.40.1017°
01:00538.413386.91.80.1017°
02:00526.810414.41.40.0917°
03:00515.28.0433.41.30.0918°
04:00494.67.2443.21.30.0918°
05:00465.07.8463.11.40.0918°
06:00446.710482.91.40.0917°
07:00418.714502.71.40.0917°
08:00391016522.51.40.0818°
09:00391219552.01.30.0819°
10:00391118591.41.30.0819°
11:00391117620.91.20.0819°
12:00401117640.81.20.0819°
13:00401017650.81.20.0819°
14:00409.916640.91.20.0819°
15:00409.416611.01.20.0819°
16:00409.015571.21.10.0719°
17:00408.614531.71.10.0718°
18:00408.414502.61.20.0717°
19:00398.414473.71.40.0817°
20:00398.714444.91.60.0816°
21:00389.515406.11.80.0816°
22:00371016367.42.00.0916°
23:00371117338.22.10.0915°

Today at a glance

Worst hour
01:00
peaks at AQI 60
Tomorrow
Much the same, peak 54
peak at 00:00

The week, hour by hour

Little changes tomorrow — the forecast peak is AQI 54 (moderate) around 00:00. The 5-day outlook reads Saturday (moderate), Sunday (moderate), Monday (good), Tuesday (moderate), and Wednesday (moderate); today is the worst day of the run.

Each cell is one forecast hour, coloured by air quality band. A ring marks the day's worst hour. The blue ring marks the current hour.

TodayOct 17
Peak 60 at 01:00
Fog24° / 12°
SunOct 18
Peak 54 at 00:00
Light rain showers19° / 15°
MonOct 19
Peak 50 at 22:00
Overcast20° / 13°
TueOct 20
Peak 53 at 23:00
Partly cloudy21° / 12°
WedOct 21
Peak 57 at 07:00
Overcast23° / 14°

Pollutants right now

Every pollutant on the same AQI scale as the big number above. The index only ever equals the worst score — pollutants don't add up.

050100150+
PM₂.₅fine particles · sets the index now
56
O₃ozone
29
PM₁₀coarse particles
18
NO₂nitrogen dioxide
5
SO₂sulfur dioxide
2
COcarbon monoxide
1
GoodModerateUnhealthy for Sensitive GroupsUnhealthyVery UnhealthyHazardous

The colors cover a wide area, not a street. The forecast works in squares of roughly 11 km across Europe and 45 km elsewhere, so the air where you actually are can differ from the shade under the city.

Check air quality in: Adelaide · Darwin

About Perth

CountryAustralia, Western Australia
TimezoneAustralia/Perth (UTC+8)
Coordinates31.95° S, 115.86° E
Population≈ 2.38M

Air quality in Perth — common questions

What is the air quality in Perth right now?

The current air quality index (AQI) in Perth is 56 (Moderate). Today's forecast peak is AQI 60 (Moderate) at 01:00 local time, and tomorrow's forecast peak is AQI 54. These values come from the CAMS forecast model, not from a local monitoring station.

When is air quality expected to be worst in Perth today?

Today's forecast puts the highest AQI in Perth at 01:00 during the night, reaching 60. The largest contributor right now is PM₂.₅. Air quality shifts through the day with traffic, wind, how well the air mixes and sunlight, so the hourly chart above shows the pattern for today and tomorrow.

What will the air quality be in Perth tomorrow?

Tomorrow's forecast peak for Perth is AQI 54 (Moderate) around 00:00 local time, much the same as today's peak of 60. A next-day forecast is less certain than today's, so check back in the morning for the updated hourly curve.

Which pollutants drive the AQI in Perth today?

The air quality index in Perth is set by PM₂.₅ right now. The modelled level this hour is 11 µg/m³, within the World Health Organization's 2021 guideline of 15 µg/m³. The others follow: O₃ (AQI 29), PM₁₀ (AQI 18), NO₂ (AQI 5), SO₂ (AQI 2), and CO (AQI 1).
Pollutant levels in Perth at the current hour
PollutantSub-indexLevelWHO 2021Vs guideline
PM₂.₅5611 µg/m³15 µg/m³ (24h)0.7×
O₃2941 µg/m³100 µg/m³ (8h)0.4×
PM₁₀1817 µg/m³45 µg/m³ (24h)0.4×
NO₂511 µg/m³25 µg/m³ (24h)0.4×
SO₂22.9 µg/m³40 µg/m³ (24h)0.1×
CO10.10 mg/m³4 mg/m³ (24h)0.03×
The overall AQI is the highest of the six sub-indices, so the pollutant with the highest sub-index is the one setting the number shown on this page. Sub-indices are computed over the EPA's averaging periods, while the levels are modelled values for the current hour.

Is air quality improving in Perth this week?

Over the 5-day forecast, daily peak AQI in Perth stays between 50 and 60. These are peak values: each day still has cleaner and dirtier hours, which the chart above shows.

How is air quality forecast for Perth, Western Australia, Australia?

Air quality for Perth is forecast with the Copernicus Atmosphere Monitoring Service (CAMS), operated by ECMWF. CAMS models hourly levels of PM2.5, PM10, ozone, nitrogen dioxide, sulfur dioxide and carbon monoxide. Perth lies at 32.0° S in the Southern Hemisphere, which sets the seasonal pattern of sunlight that drives much of the chemistry behind these pollutants. AQI values on this page use the US EPA scale.
About the Air Quality Index

What is the Air Quality Index (AQI)?

The Air Quality Index (AQI) is a tool developed by the U.S. Environmental Protection Agency (EPA) to communicate how clean or polluted the air is and what health effects may be of concern. The AQI runs from 0 to 500 and is divided into six color-coded categories: Good, Moderate, Unhealthy for Sensitive Groups, Unhealthy, Very Unhealthy, and Hazardous.

How do I read the AQI values?

Lower AQI values mean cleaner air. An AQI of 0–50 (green) is Good, 51–100 (yellow) is Moderate, 101–150 (orange) is Unhealthy for Sensitive Groups, 151–200 (red) is Unhealthy, 201–300 (purple) is Very Unhealthy, and 301–500 (maroon) is Hazardous. When the AQI exceeds 100, air quality is considered unhealthy — at first for sensitive groups, then for everyone as the AQI rises.

Who are the sensitive groups?

Sensitive groups include people with heart or lung disease, older adults, children and teenagers, people who are pregnant, and people who are active outdoors. These groups are more likely to be affected when air quality is poor. If you are in a sensitive group, you can reduce your exposure by taking fewer and shorter outdoor walks when the AQI is elevated.

Which pollutants are measured?

The AQI covers five major pollutants regulated under the Clean Air Act: ground-level ozone (O₃), particle pollution (PM₂.₅ and PM₁₀), carbon monoxide (CO), sulfur dioxide (SO₂), and nitrogen dioxide (NO₂). An AQI value is calculated for each pollutant, and the highest value determines the overall AQI.

Where does the air quality data come from?

The hourly air quality data comes from the Copernicus Atmosphere Monitoring Service (CAMS), which provides global atmospheric composition forecasts. The data is accessed via Open-Meteo, which provides free, open-source weather and air quality APIs. The AQI categories and health guidance follow the EPA AirNow technical standard (EPA-454/B-24-002).

What are the health effects of poor air quality?

Poor air quality can cause respiratory issues, aggravate asthma and allergies, and increase the risk of cardiovascular problems. Fine particles (PM₂.₅) can penetrate deep into the lungs and bloodstream. The World Health Organization estimates that air pollution causes millions of premature deaths worldwide each year.

How often is the air quality forecast updated?

The CAMS air quality forecast is updated regularly using atmospheric models. Weather data such as temperature and cloud cover comes from Open-Meteo. The forecast provides up to 5 days of hourly air quality predictions.

AQI Levels (US EPA Standard)

Good (0–50) — Air quality is satisfactory — it's a great day to be active outside
Moderate (51–100) — Unusually sensitive people should consider reducing prolonged or intense outdoor activity
Unhealthy for Sensitive Groups (101–150) — Sensitive groups should reduce prolonged or intense outdoor activity. Take more breaks and watch for symptoms such as coughing or shortness of breath
Unhealthy (151–200) — Everyone should reduce prolonged or intense outdoor activity. Sensitive groups should avoid outdoor exertion. Consider moving activities indoors
Very Unhealthy (201–300) — Everyone should avoid prolonged or intense outdoor exertion. Sensitive groups should avoid all outdoor physical activity. Move activities indoors or reschedule
Hazardous (301–500) — Health warning — everyone should avoid all outdoor physical activity. Stay indoors and keep activity levels light. Follow tips for keeping particle levels low indoors

AQI categories and health guidance: EPA AirNow (EPA-454/B-24-002, May 2024). Air quality data: CAMS/Copernicus via Open-Meteo.