SmogRank / Italy / Lombardy / Como

Como, month by month

Como has a measured daily mean on 289 days since 29 January 2024. Its worst month was February 2024, at 81 US AQI (25.0 µg/m³), 138th of 2,486 cities on that month's world ranking. Its cleanest was May 2024, at 34 US AQI (6.2 µg/m³).

Every month since 2024

2026too few days for a mean (a year needs 199)111 days measured
Jan4 daysFebnoneMarnoneApr20 daysMay48#1,081Jun20 daysJul12 daysAug14 daysSep8 daysOct53#566
2025too few days for a mean (a year needs 256)43 days measured
JannoneFebnoneMarnoneApr5 daysMay5 daysJun8 daysJul9 daysAug13 daysSep1 dayOct2 daysNovnoneDecnone
2024too few days for a mean (a year needs 257)135 days measured
Jan3 daysFeb81#138Mar12 daysApr42#1,378May34#1,947Jun10 daysJul16 daysAug10 daysSepnoneOct1 dayNovnoneDecnone
Each square is a month's mean PM2.5 in US AQI from Como's measured days, with its place on that month's world ranking under it. A month has a mean once 70% of its days are measured, the rule the monthly rankings use; under that, the square gives the days measured. Each square opens that month's ranking with Como marked; each year, the year's. A dashed square is the running month, so far.
Good0–50
Moderate51–100
Sensitive groups101–150
Unhealthy151–200
Very unhealthy201–300
Hazardous301+

The US EPA's Air Quality Index for PM2.5 (2024 breakpoints). Show values as: µg/m³ · US AQI · India AQI · China AQI · European AQI · UK DAQI · Canada AQHI+. About the scales

Months without a mean, and why

29 months
MonthWhy
Sep 20268 of 30 days measured; a month needs 21. The others: 5 with no readings from the monitor, 17 with readings for part of the day (a day needs 18 hours).
Aug 202614 of 31 days measured; a month needs 22. The others: 17 with under 18 hours of readings or readings that failed our checks.
Jul 202612 of 31 days measured; a month needs 22. The others: 19 with under 18 hours of readings or readings that failed our checks.
Jun 202620 of 30 days measured; a month needs 21. The others: 10 with under 18 hours of readings or readings that failed our checks.
Apr 202620 of 30 days measured; a month needs 21. The others: 10 with under 18 hours of readings or readings that failed our checks.
Mar 2026No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Feb 2026No day measured. The others: 28 with under 18 hours of readings or readings that failed our checks.
Jan 20264 of 31 days measured; a month needs 22. The others: 27 with under 18 hours of readings or readings that failed our checks.
Dec 2025No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Nov 2025No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Oct 20252 of 31 days measured; a month needs 22. The others: 29 with under 18 hours of readings or readings that failed our checks.
Sep 20251 of 30 days measured; a month needs 21. The others: 29 with under 18 hours of readings or readings that failed our checks.
Aug 202513 of 31 days measured; a month needs 22. The others: 18 with under 18 hours of readings or readings that failed our checks.
Jul 20259 of 31 days measured; a month needs 22. The others: 22 with under 18 hours of readings or readings that failed our checks.
Jun 20258 of 30 days measured; a month needs 21. The others: 22 with under 18 hours of readings or readings that failed our checks.
May 20255 of 31 days measured; a month needs 22. The others: 26 with under 18 hours of readings or readings that failed our checks.
Apr 20255 of 30 days measured; a month needs 21. The others: 25 with under 18 hours of readings or readings that failed our checks.
Mar 2025No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Feb 2025No day measured. The others: 28 with under 18 hours of readings or readings that failed our checks.
Jan 2025No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Dec 2024No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Nov 2024No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Oct 20241 of 31 days measured; a month needs 22. The others: 30 with under 18 hours of readings or readings that failed our checks.
Sep 2024No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Aug 202410 of 31 days measured; a month needs 22. The others: 21 with under 18 hours of readings or readings that failed our checks.
Jul 202416 of 31 days measured; a month needs 22. The others: 15 with under 18 hours of readings or readings that failed our checks.
Jun 202410 of 30 days measured; a month needs 21. The others: 20 with under 18 hours of readings or readings that failed our checks.
Mar 202412 of 31 days measured; a month needs 22. The others: 19 with under 18 hours of readings or readings that failed our checks.
Jan 20243 of 31 days measured; a month needs 22.

A day counts once 18 hours of it are measured; a month needs 70% of its days.

Como's worst months

MonthUS AQIDays measuredWorld rankEpisode
February 2024 8125.0 µg/m³26 of 29138thof 2,486Italy, Switzerland and France, February 2024
May 2026 488.7 µg/m³25 of 311,081stof 2,874–
April 2024 427.5 µg/m³29 of 301,378thof 2,520–
May 2024 346.2 µg/m³28 of 311,947thof 2,684–

Monthly means over the days measured; finished months only. World rank: its place on that month's world ranking of every city with enough days. Each month opens that ranking.

Como's worst days

DayUS AQIEpisode
18 Feb 2024 13951.1 µg/m³Italy, Switzerland and France, February 2024
23 Jan 2026 13649.7 µg/m³–
22 Jan 2026 13147.6 µg/m³–
2 Feb 2024 13047.2 µg/m³–
16 Feb 2024 12947.0 µg/m³Italy, Switzerland and France, February 2024
17 Feb 2024 12445.0 µg/m³Italy, Switzerland and France, February 2024
19 Feb 2024 12244.0 µg/m³Italy, Switzerland and France, February 2024
3 Feb 2024 12143.5 µg/m³–
4 Feb 2024 11742.0 µg/m³–
20 Feb 2024 11641.5 µg/m³Italy, Switzerland and France, February 2024

Daily means, the highest since 29 Jan 2024; the WHO's daily guideline is 15 µg/m³. Each date opens that day's world ranking, and each episode the bad-air spell it was part of.

Use this history

SmogRank, PM2.5 monthly and daily means, Como, Italy, 29 Jan 2024 – 11 Oct 2026. Monitor data from EEA, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/it/como/history (accessed 12 Oct 2026).

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You're welcome to reuse a single chart, image or figure with this citation and a link. Terms. Raw monitor readings in bulk are published by OpenAQ, under each provider's licence.

Como now: the last 24 hours, its ranks today and the last 12 months day by day.

Updated 2026-10-12 17:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index. Some low-cost readings: Sensor.Community, ODbL (data and licence). Some readings: Uzhydromet (Uzbekistan's Hydrometeorological Service); Department of Environment, Nepal; Vietnam's government monitors; Aurassure; Umhverfisstofnun (Environment Agency of Iceland); RMCAB (Secretaría Distrital de Ambiente, Bogotá); Love My Air (City and County of Denver), no reuse terms published (why we use them).