Trieste air quality now

Italy · The summary is refreshed every 15 minutes.

October 22

The air is clean now

Trieste

16°C

Partly cloudy

9AQI

1019hPa

Atmospheric
pressure

54%

Humidity

Trieste, October 21, 2026: daily mean PM2.5 5 µg/m³ (10 sensors), level “Low” — as in the Atmy Data Hub. Now (20:00 local time): 1.6 µg/m³. Open methodology and data in JSON: Methodology and data sources · JSON

Right now in Trieste, PM2.5 averages 1.6 µg/m³ — “good” on the US EPA scale (approximate, from hourly readings). Mean of 10 sensors on the Atmy network, readings from 19:52–19:56 local time (17:52–17:56 UTC), summary prepared at 20:00 local time. Median: 1.0 µg/m³; range across sensors: 0.0–9.7 µg/m³.

In Trieste the air is good right now (approximate, US EPA scale). From 07:00 to 20:00 local time the city mean PM2.5 fell from 2.7 to 1.6 µg/m³.

The wind is fairly strong (6 m/s), so particles are likely being dispersed.

Weather now: partly cloudy, 16°C, wind 6 m/s, humidity 54%. By 23:00 the wind is expected to drop to 2 m/s, and particles may build up. By 07:00 the temperature will be about 12°C.

Written automatically at 20:00 local time (18:00 UTC) from sensor measurements and the weather forecast. Values are approximate; hypotheses are marked.

22 km/h

Wind, ENE

2.1 mm

Precipitation today

Trieste: air quality for the completed day

Metric: PM2.5, µg/m³ · Color scale: EPA AQI · October 21, 2026 · 00:00–24:00 UTC

5 µg/m³ Low

Daily mean PM2.5 on October 21, 2026 (00:00–24:00 UTC): 5 µg/m³ from 10 sensors that passed the quality check — the same value as in the Atmy Data Hub.

No. 13 of 22 cities in Italy and No. 230 of 297 worldwide, from the most polluted.

LowModerateElevatedHighVery highExtremely high

Trieste: PM2.5 by month

Metric: PM2.5, µg/m³ · Color scale: EPA AQI

Mean
Oct
Nov
Dec
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
This month
6
4
8
8
12
7
10
5
4
6
5
6
4
5

Monthly means of quality-checked sensors, as in the Data Hub trend; the current month is still incomplete, “-” means no data.

Pollution accumulation index now

17%An estimate of weather conditions · not a PM2.5 forecast

Now1713
20.0004.0011.0019.00

Pollution accumulation forecast

Today — October 22

18°/13°

Index by time of day

33/100Low

  1. 33/100Night
  2. 25/100Morning
  3. 5/100Day
  4. 24/100Evening

Friday — October 23

18°/12°

Index by time of day

49/100Moderate

  1. 49/100Night
  2. 37/100Morning
  3. 7/100Day
  4. 18/100Evening

Saturday — October 24

15°/11°

Index by time of day

45/100Moderate

  1. 45/100Night
  2. 34/100Morning
  3. 4/100Day
  4. 23/100Evening

Sunday — October 25

14°/8°

Index by time of day

52/100Moderate

  1. 52/100Night
  2. 34/100Morning
  3. 8/100Day
  4. 24/100Evening

Monday — October 26

18°/9°

Index by time of day

49/100Moderate

  1. 49/100Night
  2. 33/100Morning
  3. 5/100Day
  4. 19/100Evening

Tuesday — October 27

18°/11°

Index by time of day

48/100Moderate

  1. 48/100Night
  2. 39/100Morning
  3. 9/100Day
  4. 21/100Evening

Forecast of conditions that trap pollution near the surface

Weather

16°

Partly cloudy. Feels like 11°C

  1. MorningRain16°C54%
  2. DayRain16°C53%
  3. EveningClear14°C54%

Wind

22km/hWind from the ENE

47km/hWind gusts

Wind force: 4

Gusts up to 47 km/h are expected.

10-day weather forecast for Trieste

Italy

  1. TodayOct 22Rain18°C13°C
  2. FriOct 23Thunderstorm18°C12°C
  3. SatOct 24Cloudy15°C11°C
  4. SunOct 25Rain14°C8°C
  5. MonOct 26Cloudy18°C9°C
  6. TueOct 27Cloudy18°C11°C
  7. WedOct 28Cloudy18°C11°C
  8. ThuOct 29Cloudy20°C11°C
  9. FriOct 30Partly cloudy16°C10°C
  10. SatOct 31Partly cloudy13°C8°C

Where in Trieste is the air worse?

See all sensors

Highest current reading: 9.7 µg/m³ (SC #75734). Lowest: 0.0 µg/m³ (SC #82549). The list shows every sensor, highest first.

  1. SC #75734 →10 µg/m³
  2. SC #45490 →1 µg/m³
  3. SC #86924 →1 µg/m³
  4. SC #88823 →1 µg/m³
  5. SC #83226 →1 µg/m³
  6. SC #84187 →1 µg/m³
  7. SC #35646 →0 µg/m³
  8. SC #79149 →0 µg/m³
  9. SC #52982 →0 µg/m³
  10. SC #82549 →0 µg/m³

Source: atmy.ai monitoring network

Who provides the data

Sensors in the summary by network: Sensor.Community — 10 sensors.

Atmy shows the networks’ readings after the Data Hub’s quality check: test devices and sensors that fail it are left out.

Italy: sensors in total

235

  1. VicenzaItaly

    17
  2. BolognaItaly

    15
  3. PiacenzaItaly

    14

Cities with the most sensors

All sensors on the map, by city as the map assigns them; the city’s values count only the sensors that pass the Data Hub’s quality check.

Air quality calendar: Trieste

Daily mean PM2.5 of the city sensors, µg/m³

Click a day to see its date and value.

LowModerateElevatedHighVery highExtremely high

Widget for your site

A card with the current PM2.5 in Trieste: it is refreshed every 15 minutes and links to this page. Paste the code into your site.

Air quality in Trieste now — Atmy

Questions

What was the air quality in Trieste over the last completed day?

Daily mean PM2.5 on October 21, 2026 (00:00–24:00 UTC): 5 µg/m³ from 10 sensors that passed the quality check — the same value as in the Atmy Data Hub. No. 13 of 22 cities in Italy and No. 230 of 297 worldwide, from the most polluted.

What is the air quality in Trieste right now?

Right now in Trieste, PM2.5 averages 1.6 µg/m³ — “good” on the US EPA scale (approximate, from hourly readings). Mean of 10 sensors on the Atmy network, readings from 19:52–19:56 local time (17:52–17:56 UTC), summary prepared at 20:00 local time. Median: 1.0 µg/m³; range across sensors: 0.0–9.7 µg/m³.

Is it safe to be outdoors in Trieste now?

The current level is “good” (US EPA scale, approximate). Air quality is satisfactory; no restrictions are recommended. This is the standard guidance of the scale, not medical advice.

Where in Trieste is the air worse?

Highest current reading: 9.7 µg/m³ (SC #75734). Lowest: 0.0 µg/m³ (SC #82549). The list shows every sensor, highest first.

Where do these data come from?

From Atmy sensors and connected public networks (citizen, experimental and government monitors), aggregated by Atmy. Values are approximate; see the methodology.

How often is this page updated?

The summary is rebuilt every 15 minutes from the latest reading of each sensor, each no older than one hour.

Is the air in Trieste polluted?

Over the last 365 days with data, the mean daily PM2.5 in Trieste was 6.6 µg/m³ — 1.3 times the WHO annual guideline (5 µg/m³). Over the last 30 days: 4.6 µg/m³. From Atmy's archive of daily city means.

When is the air in Trieste cleanest?

In Atmy's daily archive, the cleanest month of the last year was September 2026: 3.8 µg/m³ on average.

When is the air in Trieste most polluted?

The most polluted month of the last year was January 2026: 13.3 µg/m³ on average.

Is the air in Trieste worse in the heating season?

From November to March the mean daily PM2.5 was 9.2 µg/m³, from June to August 5.6 µg/m³ (last 365 days).

Data

Where do these data come from?

The daily value is the Data Hub’s: the mean of the city’s sensors that passed the nightly quality check, each with at least 12 valid hours, and only with sensors at four places 500 m apart; days are UTC.

“Now” uses the same sensors and rule: the mean of their latest readings, each at most 60 minutes old, shown only with sensors at four places 500 m apart reporting.

Source: public Atmy monitoring data. Methodology and data sources · Data terms