SmogRank / Spain / La Rioja / Calahorra

Calahorra, month by month

Calahorra has a measured daily mean on 428 days since 11 January 2023. Its worst month was February 2023, at 63 US AQI (15.5 µg/m³), 308th of 1,129 cities on that month's world ranking. Its cleanest was May 2024, at 22 US AQI (3.9 µg/m³).

Every month since 2023

2026too few days for a mean (a year needs 200)10 days measured
Jan4 daysFebnoneMarnoneAprnoneMay1 dayJun1 dayJulnoneAugnoneSep1 dayOct3 days
2025too few days for a mean (a year needs 256)1 day measured
JannoneFebnoneMarnoneAprnoneMaynoneJunnoneJulnoneAug1 daySepnoneOctnoneNovnoneDecnone
2024too few days for a mean (a year needs 257)131 days measured
Jan53#839Feb47#991Mar15 daysApr27#2,029May22#2,455Jun1 dayJulnoneAug1 daySepnoneOctnoneNovnoneDecnone
202346 for the year286 days measured835th of 1,355 in the world
Jan7 daysFeb63#308Mar53#239Apr44#842May43#996Jun45#1,095Jul21 daysAug14 daysSep20 daysOct28#1,741Nov26#2,030Dec44#1,292
Each square is a month's mean PM2.5 in US AQI from Calahorra'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 Calahorra 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

34 months
MonthWhy
Oct 20263 of 12 days measured; a month needs 9. The others: 2 with no readings from the monitor, 7 with readings for part of the day (a day needs 18 hours).
Sep 20261 of 30 days measured; a month needs 21. The others: 1 with no readings from the monitor, 28 with readings for part of the day (a day needs 18 hours).
Aug 2026No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Jul 2026No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Jun 20261 of 30 days measured; a month needs 21. The others: 29 with under 18 hours of readings or readings that failed our checks.
May 20261 of 31 days measured; a month needs 22. The others: 30 with under 18 hours of readings or readings that failed our checks.
Apr 2026No day measured. The others: 30 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 2025No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Sep 2025No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Aug 20251 of 31 days measured; a month needs 22. The others: 30 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 2025No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
May 2025No day measured. The others: 31 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 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 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 20241 of 31 days measured; a month needs 22. The others: 30 with under 18 hours of readings or readings that failed our checks.
Jul 2024No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Jun 20241 of 30 days measured; a month needs 21. The others: 29 with under 18 hours of readings or readings that failed our checks.
Mar 202415 of 31 days measured; a month needs 22. The others: 16 with under 18 hours of readings or readings that failed our checks.
Sep 202320 of 30 days measured; a month needs 21. The others: 10 with under 18 hours of readings or readings that failed our checks.
Aug 202314 of 31 days measured; a month needs 22. The others: 17 with under 18 hours of readings or readings that failed our checks.
Jul 202321 of 31 days measured; a month needs 22. The others: 10 with under 18 hours of readings or readings that failed our checks.
Jan 20237 of 31 days measured; a month needs 22. The others: 14 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.

Calahorra's worst months

MonthUS AQIDays measuredWorld rankEpisode
February 2023 6315.5 µg/m³27 of 28308thof 1,129Spain, France and Portugal, February 2023
January 2024 5310.4 µg/m³31 of 31839thof 2,385Europe, 27 January to 2 February 2024
March 2023 5310.2 µg/m³30 of 31239thof 911–
February 2024 478.4 µg/m³29 of 29991stof 2,486Europe, 27 January to 2 February 2024
June 2023 458.1 µg/m³28 of 301,095thof 1,603–
April 2023 447.9 µg/m³27 of 30842ndof 1,622–

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.

Calahorra's worst days

DayUS AQIEpisode
18 Feb 2023 9633.3 µg/m³Spain, France and Portugal, February 2023
20 Feb 2023 9130.4 µg/m³Spain, France and Portugal, February 2023
5 Sept 2023 8929.3 µg/m³–
21 Feb 2023 8728.3 µg/m³Spain, France and Portugal, February 2023
28 Jan 2024 8527.3 µg/m³Europe, 27 January to 2 February 2024
28 Dec 2023 8024.6 µg/m³–
17 Feb 2023 7924.2 µg/m³Spain, France and Portugal, February 2023
27 Jan 2024 7823.8 µg/m³Europe, 27 January to 2 February 2024
14 Jan 2024 7622.7 µg/m³–
14 Feb 2023 7622.6 µg/m³–

Daily means, the highest since 11 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, Calahorra, Spain, 11 Jan 2023 – 9 Oct 2026. Monitor data from EEA, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/es/calahorra/history (accessed 13 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.

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

Updated 2026-10-13 02:07 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).