SmogRank / Portugal / Porto / Freamunde

Freamunde, month by month

Freamunde has a measured daily mean on 581 days since 1 January 2023. Its worst month was January 2024, at 65 US AQI (16.8 µg/m³), 374th of 2,385 cities on that month's world ranking. Its cleanest was September 2023, at 8 US AQI (1.5 µg/m³).

Every month since 2023

2026too few days for a mean (a year needs 199)141 days measured
JannoneFeb6 daysMar18 daysApr19 daysMay12 daysJun17 daysJul18 daysAug21 daysSep27#2,432Oct5 days
2025too few days for a mean (a year needs 256)82 days measured
Jan8 daysFebnoneMarnoneAprnoneMay7 daysJun7 daysJulnoneAug39#2,132Sep20 daysOct17 daysNov1 dayDecnone
2024too few days for a mean (a year needs 257)136 days measured
Jan65#374Feb16 daysMar3 daysApr28#1,941May21 daysJun11 daysJul24#2,398Aug14 daysSepnoneOctnoneNovnoneDecnone
2023too few days for a mean (a year needs 256)222 days measured
Jan14 daysFeb2 daysMar11 daysApr11 daysMay24#1,497Jun24#1,476Jul12#1,424Aug14#1,977Sep8#2,174Oct18 daysNov56#293Dec20 days
Each square is a month's mean PM2.5 in US AQI from Freamunde'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 Freamunde marked; each year, the year's.
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

35 months
MonthWhy
Oct 20265 of 11 days measured; a month needs 8. The others: 5 with no readings from the monitor, 1 with readings for part of the day (a day needs 18 hours).
Aug 202621 of 31 days measured; a month needs 22. The others: 10 with under 18 hours of readings or readings that failed our checks.
Jul 202618 of 31 days measured; a month needs 22. The others: 13 with under 18 hours of readings or readings that failed our checks.
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 202612 of 31 days measured; a month needs 22. The others: 19 with under 18 hours of readings or readings that failed our checks.
Apr 202619 of 30 days measured; a month needs 21. The others: 11 with under 18 hours of readings or readings that failed our checks.
Mar 202618 of 31 days measured; a month needs 22. The others: 13 with under 18 hours of readings or readings that failed our checks.
Feb 20266 of 28 days measured; a month needs 20. The others: 22 with under 18 hours of readings or readings that failed our checks.
Jan 2026No day measured. The others: 31 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 20251 of 30 days measured; a month needs 21. The others: 29 with under 18 hours of readings or readings that failed our checks.
Oct 202517 of 31 days measured; a month needs 22. The others: 14 with under 18 hours of readings or readings that failed our checks.
Sep 202520 of 30 days measured; a month needs 21. The others: 10 with under 18 hours of readings or readings that failed our checks.
Jul 2025No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Jun 20257 of 30 days measured; a month needs 21. The others: 23 with under 18 hours of readings or readings that failed our checks.
May 20257 of 31 days measured; a month needs 22. The others: 24 with under 18 hours of readings or readings that failed our checks.
Apr 2025No day measured. The others: 30 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 20258 of 31 days measured; a month needs 22. The others: 23 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 2024No day measured. The others: 31 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 202414 of 31 days measured; a month needs 22. The others: 17 with under 18 hours of readings or readings that failed our checks.
Jun 202411 of 30 days measured; a month needs 21. The others: 19 with under 18 hours of readings or readings that failed our checks.
May 202421 of 31 days measured; a month needs 22. The others: 10 with under 18 hours of readings or readings that failed our checks.
Mar 20243 of 31 days measured; a month needs 22. The others: 28 with under 18 hours of readings or readings that failed our checks.
Feb 202416 of 29 days measured; a month needs 21. The others: 1 missing from OpenAQ's archive, 12 with under 18 hours of readings or readings that failed our checks.
Dec 202320 of 31 days measured; a month needs 22. The others: 11 with under 18 hours of readings or readings that failed our checks.
Oct 202318 of 31 days measured; a month needs 22. The others: 13 with under 18 hours of readings or readings that failed our checks.
Apr 202311 of 30 days measured; a month needs 21. The others: 3 missing from OpenAQ's archive, 16 with under 18 hours of readings or readings that failed our checks.
Mar 202311 of 31 days measured; a month needs 22. The others: 20 missing from OpenAQ's archive.
Feb 20232 of 28 days measured; a month needs 20. The others: 25 missing from OpenAQ's archive, 1 with under 18 hours of readings or readings that failed our checks.
Jan 202314 of 31 days measured; a month needs 22. The others: 7 missing from OpenAQ's archive, 10 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.

Freamunde's worst months

MonthUS AQIDays measuredWorld rankEpisode
January 2024 6516.8 µg/m³24 of 31374thof 2,385Europe, 27 January to 2 February 2024
Spain, France and 2 more countries, December 2023 to January 2024
November 2023 5612.0 µg/m³24 of 30293rdof 2,243–
August 2025 397.1 µg/m³22 of 312,132ndof 2,901–
April 2024 285.1 µg/m³23 of 301,941stof 2,520–
September 2026 274.8 µg/m³25 of 302,432ndof 2,981–
May 2023 244.3 µg/m³25 of 311,497thof 1,600–

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.

Freamunde's worst days

DayUS AQIEpisode
6 Feb 2024 15764.5 µg/m³Southern Europe, February 2024
26 Nov 2023 14653.8 µg/m³–
25 Nov 2023 13750.1 µg/m³–
30 Jan 2024 12143.7 µg/m³Europe, 27 January to 2 February 2024
5 Feb 2024 12143.6 µg/m³Southern Europe, February 2024
15 Jan 2025 10938.9 µg/m³–
3 Jan 2023 10838.3 µg/m³–
22 Dec 2023 10838.2 µg/m³–
27 Nov 2023 10738.0 µg/m³–
21 Dec 2023 10737.9 µg/m³–

Daily means, the highest since 1 Jan 2023; 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, Freamunde, Portugal, 1 Jan 2023 – 5 Oct 2026. Monitor data from EEA, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/pt/freamunde/history (accessed 12 Oct 2026).

Download chart (PNG)

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.

Freamunde 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).