SmogRank / United Kingdom / England / Southend-on-Sea

Southend-on-Sea, month by month

Southend-on-Sea has a measured daily mean on 40 days since 1 January 2023. Its worst month was January 2023, at 47 US AQI (8.5 µg/m³), 637th of 1,261 cities on that month's world ranking.

Every month since 2023

2026too few days for a mean (a year needs 200)13 days measured
JannoneFebnoneMarnoneAprnoneMaynoneJunnoneJulnoneAugnoneSep1 dayOct23#2,385
2025too few days for a mean (a year needs 256)0 days measured
JannoneFebnoneMarnoneAprnoneMaynoneJunnoneJulnoneAugnoneSepnoneOctnoneNovnoneDecnone
2024too few days for a mean (a year needs 257)0 days measured
JannoneFebnoneMarnoneAprnoneMaynoneJunnoneJulnoneAugnoneSepnoneOctnoneNovnoneDecnone
2023too few days for a mean (a year needs 256)27 days measured
Jan47#637Feb2 daysMarnoneAprnoneMaynoneJunnoneJulnoneAugnoneSepnoneOctnoneNovnoneDecnone
Each square is a month's mean PM2.5 in US AQI from Southend-on-Sea'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 Southend-on-Sea 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

44 months
MonthWhy
Sep 20261 of 30 days measured; a month needs 21. The others: 29 with under 18 hours of readings or readings that failed our checks.
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 2026No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
May 2026No day measured. The others: 31 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 2026No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Dec 2025No day measured.
Nov 2025No day measured.
Oct 2025No day measured.
Sep 2025No day measured.
Aug 2025No day measured.
Jul 2025No day measured.
Jun 2025No day measured.
May 2025No day measured.
Apr 2025No day measured.
Mar 2025No day measured.
Feb 2025No day measured.
Jan 2025No day measured.
Dec 2024No day measured.
Nov 2024No day measured.
Oct 2024No day measured.
Sep 2024No day measured.
Aug 2024No day measured.
Jul 2024No day measured.
Jun 2024No day measured.
May 2024No day measured.
Apr 2024No day measured.
Mar 2024No day measured.
Feb 2024No day measured.
Jan 2024No day measured.
Dec 2023No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Nov 2023No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Oct 2023No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Sep 2023No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Aug 2023No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Jul 2023No day measured. The others: 1 missing from OpenAQ's archive, 30 with under 18 hours of readings or readings that failed our checks.
Jun 2023No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
May 2023No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Apr 2023No day measured. The others: 3 missing from OpenAQ's archive, 27 with under 18 hours of readings or readings that failed our checks.
Mar 2023No day measured. The others: 20 missing from OpenAQ's archive, 11 with under 18 hours of readings or readings that failed our checks.
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.

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

Southend-on-Sea's worst months

MonthUS AQIDays measuredWorld rank
January 2023 478.5 µg/m³25 of 31637thof 1,261

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.

Southend-on-Sea's worst days

DayUS AQI
14 Feb 2023 11039.0 µg/m³
15 Feb 2023 10035.4 µg/m³
25 Jan 2023 7421.7 µg/m³
21 Jan 2023 6918.9 µg/m³
24 Jan 2023 6114.2 µg/m³
23 Jan 2023 6014.0 µg/m³
17 Jan 2023 5611.7 µg/m³
28 Jan 2023 5410.9 µg/m³
29 Jan 2023 5410.7 µg/m³
18 Jan 2023 529.6 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, Southend-on-Sea, United Kingdom, 1 Jan 2023 – 12 Oct 2026. Monitor data from UK-AIR (Defra), read from the publisher; sources listed at smogrank.com/sources. smogrank.com/gb/southend-on-sea/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.

Southend-on-Sea 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).