SmogRank / Italy / Piedmont / Biella

Biella, month by month

Biella has a measured daily mean on 236 days since 6 May 2025. Its worst month was August 2026, at 55 US AQI (11.3 µg/m³), 651st of 2,896 cities on that month's world ranking. Its cleanest was September 2025, at 33 US AQI (6.0 µg/m³).

Every month since 2025

2026too few days for a mean (a year needs 199)137 days measured
Jan2 daysFebnoneMar1 dayApr52#1,058May13 daysJun17 daysJul51#1,562Aug55#651Sep20 daysOct53#553
2025too few days for a mean (a year needs 256)99 days measured
JanFebMarAprMay8 daysJun13 daysJul35#2,207Aug51#1,398Sep33#2,096Oct4 daysNovnoneDecnone
Each square is a month's mean PM2.5 in US AQI from Biella'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 Biella 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

11 months
MonthWhy
Sep 202620 of 30 days measured; a month needs 21. The others: 10 with readings for part of the day (a day needs 18 hours).
Jun 202617 of 30 days measured; a month needs 21. The others: 13 with under 18 hours of readings or readings that failed our checks.
May 202613 of 31 days measured; a month needs 22. The others: 18 with under 18 hours of readings or readings that failed our checks.
Mar 20261 of 31 days measured; a month needs 22. The others: 30 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 20262 of 31 days measured; a month needs 22. The others: 29 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 20254 of 31 days measured; a month needs 22. The others: 27 with under 18 hours of readings or readings that failed our checks.
Jun 202513 of 30 days measured; a month needs 21. The others: 17 with under 18 hours of readings or readings that failed our checks.
May 20258 of 31 days measured; a month needs 22. The others: 18 with under 18 hours of readings or readings that failed our checks.

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

Biella's worst months

MonthUS AQIDays measuredWorld rank
August 2026 5511.3 µg/m³22 of 31651stof 2,896
April 2026 529.5 µg/m³22 of 301,058thof 2,941
August 2025 519.3 µg/m³25 of 311,398thof 2,901
July 2026 519.2 µg/m³29 of 311,562ndof 2,784
July 2025 356.3 µg/m³23 of 312,207thof 2,889
September 2025 336.0 µg/m³26 of 302,096thof 3,104

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.

Biella's worst days

DayUS AQIEpisode
14 Jun 2025 8326.1 µg/m³Italy, France and 2 more countries, June 2025
13 Aug 2026 7622.4 µg/m³–
23 Jan 2026 7421.6 µg/m³–
12 Aug 2026 7320.8 µg/m³–
21 Jan 2026 7019.2 µg/m³–
14 Oct 2025 7019.1 µg/m³–
8 Aug 2026 6717.9 µg/m³–
23 Oct 2025 6717.6 µg/m³–
11 Jun 2025 6717.5 µg/m³–
14 Aug 2026 6617.3 µg/m³–

Daily means, the highest since 6 May 2025; 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, Biella, Italy, 6 May 2025 – 11 Oct 2026. Monitor data from EEA, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/it/biella/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.

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

Updated 2026-10-12 18:07 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).