SmogRank / Sweden / Stockholm / Södertälje

Södertälje, month by month

Södertälje has a measured daily mean on 341 days since 6 March 2025. Its worst month was March 2026, at 56 US AQI (12.0 µg/m³), 1,214th of 2,971 cities on that month's world ranking. Its cleanest was August 2025, at 19 US AQI (3.5 µg/m³).

Every month since 2025

2026too few days for a mean (a year needs 200)102 days measured
Jan16 daysFeb29#2,557Mar56#1,214Apr5 daysMay10 daysJun15 daysJul2 daysAugnoneSepnoneOct1 day
2025too few days for a mean (a year needs 256)239 days measured
JanFebMar52#1,646Apr36#2,187May20#2,675Jun18 daysJul36#2,135Aug19#2,850Sep26#2,768Oct24#2,280Nov22#2,582Dec9 days
Each square is a month's mean PM2.5 in US AQI from Södertälje'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 Södertälje 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

10 months
MonthWhy
Oct 20261 of 12 days measured; a month needs 9. The others: 11 with readings for part of the day (a day needs 18 hours).
Sep 2026No day measured. The others: 1 with no readings from the monitor, 29 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 20262 of 31 days measured; a month needs 22. The others: 29 with under 18 hours of readings or readings that failed our checks.
Jun 202615 of 30 days measured; a month needs 21. The others: 15 with under 18 hours of readings or readings that failed our checks.
May 202610 of 31 days measured; a month needs 22. The others: 21 with under 18 hours of readings or readings that failed our checks.
Apr 20265 of 30 days measured; a month needs 21. The others: 25 with under 18 hours of readings or readings that failed our checks.
Jan 202616 of 31 days measured; a month needs 22. The others: 15 with under 18 hours of readings or readings that failed our checks.
Dec 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 202518 of 30 days measured; a month needs 21. The others: 12 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.

Södertälje's worst months

MonthUS AQIDays measuredWorld rankEpisode
March 2026 5612.0 µg/m³27 of 311,214thof 2,971Europe, 1 to 12 March 2026
March 2025 529.7 µg/m³22 of 311,646thof 2,862–
July 2025 366.5 µg/m³31 of 312,135thof 2,889–
April 2025 366.4 µg/m³27 of 302,187thof 2,951–
February 2026 295.3 µg/m³26 of 282,557thof 2,866–
September 2025 264.6 µg/m³26 of 302,768thof 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.

Södertälje's worst days

DayUS AQIEpisode
11 Mar 2026 9633.2 µg/m³Europe, 1 to 12 March 2026
19 Mar 2026 8728.5 µg/m³–
9 Mar 2026 8326.5 µg/m³Europe, 1 to 12 March 2026
10 Mar 2026 8326.1 µg/m³Europe, 1 to 12 March 2026
2 Apr 2025 7924.2 µg/m³–
8 Mar 2025 7421.4 µg/m³–
1 Apr 2025 7019.1 µg/m³–
17 Jan 2026 6918.7 µg/m³–
20 Jan 2026 6818.3 µg/m³–
19 Jan 2026 6818.0 µg/m³–

Daily means, the highest since 6 Mar 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, Södertälje, Sweden, 6 Mar 2025 – 10 Oct 2026. Monitor data from EEA, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/se/soedertaelje/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.

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

Updated 2026-10-12 22:07 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).