Air quality index for Milan, as of (Europe/Rome). Values update hourly — see this page for the current reading and hourly forecast. Today's peak: AQI 155 at 00:00 local time.

airindex·today

Air Quality in Milan

Milan is now at AQI 151 (unhealthy), below today's high of AQI 155 in the same band around 00:00. Today's main contributor is fine particulate matter (PM₂.₅), at 38 µg/m³. That concentration is about 2.5× the WHO 24-hour guideline of 15 µg/m³. The index stays above 100 for the whole day. Little changes hour to hour: today's values stay between AQI 146 and AQI 155.

Now, Oct 17at 20:00
151Unhealthy
Good0–50
Moderate51–100
Sensitive groups101–150
Unhealthy151–200
Very unhealthy201–300
Hazardous301+

By pollutant

  • PM₂.₅ fine particles · sets the index nowAQI 151
  • PM₁₀ coarse particlesAQI 55
  • O₃ ozoneAQI 42
  • NO₂ nitrogen dioxideAQI 31
  • SO₂ sulfur dioxideAQI 2
  • CO carbon monoxideAQI 2
Everyone should reduce prolonged or intense outdoor activity
Sensitive groups should avoid outdoor exertion
Consider moving activities indoors

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 Milan · Local time (GMT+2)

Today, Oct 17
Tomorrow, Oct 18
50
100
150
Peak 155 · 00:00
Peak 143 · 00:00
0:00
6:00
12:00
18:00
0:00
6:00
12:00
18:00

Good ≤ 50 · Moderate ≤ 100 · Sensitive groups ≤ 150

Now
Show hourly data table
TimeAQIPM₂.₅µg/m³PM₁₀µg/m³O₃µg/m³NO₂µg/m³SO₂µg/m³COmg/m³°C
Today
00:00155627148442.80.3516°
01:00155626946322.60.3116°
02:00155606939312.70.3116°
03:00155637034272.50.3115°
04:00155667434252.70.3015°
05:00155677638232.60.2914°
06:00155677633233.10.2814°
07:00155677627303.30.3014°
08:00155708016323.90.3314°
09:00155738421374.10.3215°
10:00155647336303.90.3016°
11:00155556358253.50.2818°
12:00155536070193.50.2519°
13:00154515584142.90.2320°
14:00154475096122.40.2021°
15:0015443471039.01.90.2021°
16:0015337451088.71.70.2021°
17:0015332401089.81.70.2021°
18:00152334090191.90.2220°
19:00152354462462.60.2619°
20:00151384636623.00.2718°
21:00150434820742.80.2917°
22:00148404635502.70.2517°
23:00146384336462.20.2617°
Tomorrow
00:00143364233341.90.2617°
01:00141354030361.70.2717°
02:00138343836291.70.2617°
03:00135293450251.30.2216°
04:00131262849201.20.2116°
05:00127222345161.10.2016°
06:00122202142131.20.1916°
07:00117202144121.30.1815°
08:00112202244141.50.1815°
09:00107182052141.30.1815°
10:00102192058131.10.1816°
11:0097181960121.00.1816°
12:00941719669.50.90.1816°
13:00911316718.90.70.1716°
14:00881215786.90.70.1716°
15:00841317825.60.80.1617°
16:00821215816.50.70.1718°
17:00801215818.50.80.1717°
18:0078111478111.00.1817°
19:0076121475131.00.1916°
20:0074121466151.00.1916°
21:0071101367130.90.1816°
22:00699.51172110.80.1716°
23:00668.910739.50.70.1717°

Today at a glance

Worst stretch
All day
peaks at AQI 155
Tomorrow
Better, peak 143
peak at 00:00

The week, hour by hour

Tomorrow eases, with the forecast peak down to AQI 143 (unhealthy for sensitive groups) around 00:00. The 5-day outlook reads Saturday (unhealthy), Sunday (unhealthy for sensitive groups), Monday (moderate), 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 155 at 00:00
Overcast21° / 14°
SunOct 18
Peak 143 at 00:00
Light rain showers18° / 15°
MonOct 19
Peak 63 at 00:00
Overcast21° / 15°
TueOct 20
Peak 83 at 15:00
Rain19° / 14°
WedOct 21
Peak 85 at 03:00
Thunderstorm18° / 15°

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
151
PM₁₀coarse particles
55
O₃ozone
42
NO₂nitrogen dioxide
31
SO₂sulfur dioxide
2
COcarbon monoxide
2
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: Parma · Bergamo · Brescia · Novara · Monza

About Milan

CountryItaly, Lombardy
TimezoneEurope/Rome (UTC+2)
Coordinates45.46° N, 9.19° E
Population≈ 1.37M

Air quality in Milan — common questions

What is the air quality in Milan right now?

The current air quality index (AQI) in Milan is 151 (Unhealthy). Today's forecast peak is AQI 155 (Unhealthy) at 00:00 local time, and tomorrow's forecast peak is AQI 143. These values come from the CAMS forecast model, not from a local monitoring station.

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

Today's forecast puts the highest AQI in Milan at 00:00 during the night, reaching 155. 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 Milan tomorrow?

Tomorrow's forecast peak for Milan is AQI 143 (Unhealthy for Sensitive Groups) around 00:00 local time, lower than today's peak of 155. 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 Milan today?

The air quality index in Milan is set by PM₂.₅ right now. The modelled level this hour is 38 µg/m³ — 2.5× the World Health Organization's 2021 guideline of 15 µg/m³. The others follow: PM₁₀ (AQI 55), O₃ (AQI 42), NO₂ (AQI 31), SO₂ (AQI 2), and CO (AQI 2).
Pollutant levels in Milan at the current hour
PollutantSub-indexLevelWHO 2021Vs guideline
PM₂.₅15138 µg/m³15 µg/m³ (24h)2.5×
PM₁₀5546 µg/m³45 µg/m³ (24h)1.0×
O₃4236 µg/m³100 µg/m³ (8h)0.4×
NO₂3162 µg/m³25 µg/m³ (24h)2.5×
SO₂23.0 µg/m³40 µg/m³ (24h)0.1×
CO20.27 mg/m³4 mg/m³ (24h)0.1×
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 Milan this week?

Over the 5-day forecast, daily peak AQI in Milan stays between 63 and 155. These are peak values: each day still has cleaner and dirtier hours, which the chart above shows.

How is air quality forecast for Milan, Lombardy, Italy?

Air quality for Milan 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. Milan lies at 45.5° N in the Northern 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.