SmogRank / Jersey / St Helier

Air quality in Saint Helier

St Helier, Jersey. PM2.5 from 34 low-cost sensors, updated hourly.

0.6 µg/m³
Good

Latest hour (04:00 UTC), 0.0× the WHO 24-hour guideline.

Rank

24 h
–
not enough data
7 days
#1,782
of 2,330 · 5.2 µg/m³
30 days
#2,245
of 2,327 · 3.2 µg/m³
Year
–
not enough data

Last 4 days, hour by hour

15302026-09-30 23:00 UTC: 0.7 µg/m³2026-10-01 00:00 UTC: 0.7 µg/m³2026-10-01 01:00 UTC: 0.6 µg/m³2026-10-01 03:00 UTC: 0.5 µg/m³2026-10-01 04:00 UTC: 0.6 µg/m³Sep 28Sep 29Sep 30Oct 1

Times in UTC. Dashed line: WHO 24-hour guideline (15 µg/m³).

Every day for a year

SepNovDecJanFebMarAprMayJunJulAugSepMonWedFri2025-09-29: 4.8 µg/m³2025-09-30: 7.3 µg/m³2025-10-01: 13.5 µg/m³2025-10-02: 12.5 µg/m³2025-10-03: 6.0 µg/m³2025-10-04: 2.3 µg/m³2025-10-05: 1.6 µg/m³2025-10-06: 2.2 µg/m³2025-10-07: no data2025-10-08: 6.1 µg/m³2025-10-09: 3.7 µg/m³2025-10-10: 9.4 µg/m³2025-10-11: no data2025-10-12: 22.2 µg/m³2025-10-13: 14.5 µg/m³2025-10-14: 5.7 µg/m³2025-10-15: 1.9 µg/m³2025-10-16: 8.2 µg/m³2025-10-17: 11.0 µg/m³2025-10-18: 7.1 µg/m³2025-10-19: no data2025-10-20: no data2025-10-21: 1.4 µg/m³2025-10-22: 2.0 µg/m³2025-10-23: 1.3 µg/m³2025-10-24: no data2025-10-25: no data2025-10-26: 0.9 µg/m³2025-10-27: no data2025-10-28: 1.1 µg/m³2025-10-29: 2.2 µg/m³2025-10-30: no data2025-10-31: 3.1 µg/m³2025-11-01: 1.5 µg/m³2025-11-02: no data2025-11-03: no data2025-11-04: 5.1 µg/m³2025-11-05: 3.9 µg/m³2025-11-06: 4.5 µg/m³2025-11-07: 4.5 µg/m³2025-11-08: 4.8 µg/m³2025-11-09: 2.9 µg/m³2025-11-10: 2.0 µg/m³2025-11-11: 4.1 µg/m³2025-11-12: 5.7 µg/m³2025-11-13: no data2025-11-14: no data2025-11-15: 5.8 µg/m³2025-11-16: 5.3 µg/m³2025-11-17: 2.5 µg/m³2025-11-18: 2.0 µg/m³2025-11-19: 0.9 µg/m³2025-11-20: 0.8 µg/m³2025-11-21: 6.4 µg/m³2025-11-22: no data2025-11-23: no data2025-11-24: 1.4 µg/m³2025-11-25: 1.1 µg/m³2025-11-26: 2.0 µg/m³2025-11-27: 1.9 µg/m³2025-11-28: 2.7 µg/m³2025-11-29: 1.9 µg/m³2025-11-30: 1.4 µg/m³2025-12-01: 2.6 µg/m³2025-12-02: 1.3 µg/m³2025-12-03: 5.7 µg/m³2025-12-04: 2.4 µg/m³2025-12-05: 3.5 µg/m³2025-12-06: no data2025-12-07: 3.5 µg/m³2025-12-08: 2.7 µg/m³2025-12-09: 5.1 µg/m³2025-12-10: 4.3 µg/m³2025-12-11: 10.4 µg/m³2025-12-12: 8.9 µg/m³2025-12-13: 9.2 µg/m³2025-12-14: 15.2 µg/m³2025-12-15: no data2025-12-16: no data2025-12-17: 3.9 µg/m³2025-12-18: no data2025-12-19: 1.8 µg/m³2025-12-20: 5.5 µg/m³2025-12-21: 8.2 µg/m³2025-12-22: 2.1 µg/m³2025-12-23: no data2025-12-24: no data2025-12-25: 15.3 µg/m³2025-12-26: 27.5 µg/m³2025-12-27: 26.3 µg/m³2025-12-28: 18.9 µg/m³2025-12-29: no data2025-12-30: 2.0 µg/m³2025-12-31: 7.5 µg/m³2026-01-01: 3.7 µg/m³2026-01-02: 1.5 µg/m³2026-01-03: 1.3 µg/m³2026-01-04: 7.7 µg/m³2026-01-05: 2.1 µg/m³2026-01-06: 2.8 µg/m³2026-01-07: 2.0 µg/m³2026-01-08: 5.3 µg/m³2026-01-09: 1.8 µg/m³2026-01-10: 9.8 µg/m³2026-01-11: 5.5 µg/m³2026-01-12: 3.1 µg/m³2026-01-13: 10.2 µg/m³2026-01-14: 13.5 µg/m³2026-01-15: 3.2 µg/m³2026-01-16: 2.2 µg/m³2026-01-17: 11.9 µg/m³2026-01-18: 20.6 µg/m³2026-01-19: 19.3 µg/m³2026-01-20: 3.5 µg/m³2026-01-21: 3.5 µg/m³2026-01-22: 2.7 µg/m³2026-01-23: 3.0 µg/m³2026-01-24: 3.0 µg/m³2026-01-25: 4.5 µg/m³2026-01-26: 7.9 µg/m³2026-01-27: 3.7 µg/m³2026-01-28: 4.0 µg/m³2026-01-29: 10.9 µg/m³2026-01-30: 3.9 µg/m³2026-01-31: 2.9 µg/m³2026-02-01: 2.5 µg/m³2026-02-02: 3.4 µg/m³2026-02-03: 3.7 µg/m³2026-02-04: no data2026-02-05: 4.4 µg/m³2026-02-06: 3.7 µg/m³2026-02-07: 3.0 µg/m³2026-02-08: no data2026-02-09: 6.5 µg/m³2026-02-10: 3.9 µg/m³2026-02-11: no data2026-02-12: 4.1 µg/m³2026-02-13: 4.3 µg/m³2026-02-14: 4.0 µg/m³2026-02-15: 3.8 µg/m³2026-02-16: no data2026-02-17: 2.5 µg/m³2026-02-18: 4.5 µg/m³2026-02-19: no data2026-02-20: 3.8 µg/m³2026-02-21: 2.6 µg/m³2026-02-22: no data2026-02-23: 3.1 µg/m³2026-02-24: 5.4 µg/m³2026-02-25: 10.0 µg/m³2026-02-26: 6.1 µg/m³2026-02-27: 2.8 µg/m³2026-02-28: 2.7 µg/m³2026-03-01: 2.3 µg/m³2026-03-02: 9.3 µg/m³2026-03-03: 18.8 µg/m³2026-03-04: 21.5 µg/m³2026-03-05: no data2026-03-06: 23.3 µg/m³2026-03-07: 31.0 µg/m³2026-03-08: 38.5 µg/m³2026-03-09: 21.8 µg/m³2026-03-10: 10.1 µg/m³2026-03-11: 3.5 µg/m³2026-03-12: 3.6 µg/m³2026-03-13: 2.4 µg/m³2026-03-14: 4.3 µg/m³2026-03-15: 4.2 µg/m³2026-03-16: 3.9 µg/m³2026-03-17: 4.2 µg/m³2026-03-18: 4.2 µg/m³2026-03-19: 20.4 µg/m³2026-03-20: 32.4 µg/m³2026-03-21: 22.4 µg/m³2026-03-22: 16.2 µg/m³2026-03-23: 25.3 µg/m³2026-03-24: 21.1 µg/m³2026-03-25: no data2026-03-26: 2.2 µg/m³2026-03-27: 2.3 µg/m³2026-03-28: 3.3 µg/m³2026-03-29: no data2026-03-30: 3.9 µg/m³2026-03-31: 6.2 µg/m³2026-04-01: 2.3 µg/m³2026-04-02: 2.2 µg/m³2026-04-03: 7.0 µg/m³2026-04-04: 4.3 µg/m³2026-04-05: no data2026-04-06: no data2026-04-07: no data2026-04-08: no data2026-04-09: no data2026-04-10: no data2026-04-11: no data2026-04-12: no data2026-04-13: no data2026-04-14: no data2026-04-15: no data2026-04-16: no data2026-04-17: no data2026-04-18: 1.9 µg/m³2026-04-19: 1.0 µg/m³2026-04-20: no data2026-04-21: no data2026-04-22: no data2026-04-23: no data2026-04-24: no data2026-04-25: 8.0 µg/m³2026-04-26: no data2026-04-27: no data2026-04-28: no data2026-04-29: no data2026-04-30: no data2026-05-01: 14.9 µg/m³2026-05-02: no data2026-05-03: no data2026-05-04: no data2026-05-05: no data2026-05-06: no data2026-05-07: no data2026-05-08: no data2026-05-09: no data2026-05-10: 11.9 µg/m³2026-05-11: 1.9 µg/m³2026-05-12: 3.4 µg/m³2026-05-13: no data2026-05-14: 1.6 µg/m³2026-05-15: no data2026-05-16: no data2026-05-17: no data2026-05-18: no data2026-05-19: no data2026-05-20: 7.2 µg/m³2026-05-21: 7.3 µg/m³2026-05-22: 5.5 µg/m³2026-05-23: no data2026-05-24: 3.9 µg/m³2026-05-25: 8.9 µg/m³2026-05-26: no data2026-05-27: no data2026-05-28: no data2026-05-29: no data2026-05-30: no data2026-05-31: no data2026-06-01: 3.5 µg/m³2026-06-02: no data2026-06-03: no data2026-06-04: no data2026-06-05: no data2026-06-06: no data2026-06-07: no data2026-06-08: no data2026-06-09: no data2026-06-10: 0.8 µg/m³2026-06-11: no data2026-06-12: no data2026-06-13: no data2026-06-14: no data2026-06-15: no data2026-06-16: no data2026-06-17: no data2026-06-18: no data2026-06-19: no data2026-06-20: no data2026-06-21: no data2026-06-22: no data2026-06-23: no data2026-06-24: no data2026-06-25: no data2026-06-26: no data2026-06-27: no data2026-06-28: 1.8 µg/m³2026-06-29: 1.4 µg/m³2026-06-30: no data2026-07-01: 1.5 µg/m³2026-07-02: no data2026-07-03: no data2026-07-04: no data2026-07-05: no data2026-07-06: no data2026-07-07: no data2026-07-08: no data2026-07-09: no data2026-07-10: no data2026-07-11: no data2026-07-12: 15.1 µg/m³2026-07-13: 7.9 µg/m³2026-07-14: 9.8 µg/m³2026-07-15: 10.5 µg/m³2026-07-16: no data2026-07-17: no data2026-07-18: no data2026-07-19: no data2026-07-20: no data2026-07-21: no data2026-07-22: no data2026-07-23: no data2026-07-24: no data2026-07-25: no data2026-07-26: no data2026-07-27: no data2026-07-28: no data2026-07-29: no data2026-07-30: no data2026-07-31: no data2026-08-01: no data2026-08-02: no data2026-08-03: no data2026-08-04: no data2026-08-05: no data2026-08-06: no data2026-08-07: no data2026-08-08: no data2026-08-09: no data2026-08-10: no data2026-08-11: no data2026-08-12: no data2026-08-13: no data2026-08-14: 4.6 µg/m³2026-08-15: 3.5 µg/m³2026-08-16: 8.1 µg/m³2026-08-17: no data2026-08-18: no data2026-08-19: no data2026-08-20: no data2026-08-21: no data2026-08-22: no data2026-08-23: no data2026-08-24: 5.8 µg/m³2026-08-25: 5.4 µg/m³2026-08-26: 8.2 µg/m³2026-08-27: 2.1 µg/m³2026-08-28: 1.8 µg/m³2026-08-29: no data2026-08-30: 1.8 µg/m³2026-08-31: 1.8 µg/m³2026-09-01: 1.6 µg/m³2026-09-02: no data2026-09-03: 1.7 µg/m³2026-09-04: 1.8 µg/m³2026-09-05: 1.8 µg/m³2026-09-06: 2.2 µg/m³2026-09-07: 2.5 µg/m³2026-09-08: 1.4 µg/m³2026-09-09: no data2026-09-10: no data2026-09-11: no data2026-09-12: no data2026-09-13: 2.0 µg/m³2026-09-14: 2.8 µg/m³2026-09-15: 4.3 µg/m³2026-09-16: 1.5 µg/m³2026-09-17: no data2026-09-18: 3.2 µg/m³2026-09-19: 2.3 µg/m³2026-09-20: 2.1 µg/m³2026-09-21: 3.5 µg/m³2026-09-22: 3.2 µg/m³2026-09-23: 3.8 µg/m³2026-09-24: 3.6 µg/m³2026-09-25: 8.9 µg/m³2026-09-26: 1.4 µg/m³2026-09-27: 8.6 µg/m³2026-09-28: 2.1 µg/m³2026-09-29: 8.7 µg/m³2026-09-30: 2.8 µg/m³
Good 0–9.0Moderate 9.1+Unhealthy for sensitive groups 35.5+Unhealthy 55.5+Very unhealthy 125.5+Hazardous 225.5+No data

21 of 212 measured days were over the WHO 24-hour guideline.

Daily world rank

#1#2366OctNovDecJanFebMarAprMayJunJulAugSep

Rank on each day's board (1 = most polluted city that day).

2026 against 2025, month by month

15Jan 2025: 11.9 µg/m³Jan 2026: 5.8 µg/m³JanFeb 2025: 19.0 µg/m³Feb 2026: 4.1 µg/m³FebMar 2025: 13.5 µg/m³Mar 2026: 13.0 µg/m³MarApr 2025: 11.1 µg/m³AprMay 2025: 6.6 µg/m³May 2026: 6.7 µg/m³MayJun 2025: 6.1 µg/m³JunJul 2025: 4.7 µg/m³JulAug 2025: 5.0 µg/m³Aug 2026: 4.3 µg/m³AugSep 2025: 2.7 µg/m³Sep 2026: 3.2 µg/m³SepOct 2025: 6.1 µg/m³OctNov 2025: 3.1 µg/m³NovDec 2025: 8.1 µg/m³Dec

Faded bars: 2025. A month shows once it has 10 measured days.

This week against past years

This weekThis week: 5.2 µg/m³5.220252025: 4.6 µg/m³4.6

Mean PM2.5 for 24 Sept to 30 Sept in each year. Dashed line: WHO 24-hour guideline.

Monitors

StationOperatorType
Next to Green St roundabout and tunnel CC0 1.0ClarityLow-cost
Auvergne schoolCC0 1.0ClarityLow-cost
mont millaisCC0 1.0ClarityLow-cost
Five oaks CC0 1.0ClarityLow-cost
Bottom of Mont MillaisCC0 1.0ClarityLow-cost
Beaumont Roundabout (bottom)CC0 1.0ClarityLow-cost
Beaumont Hill (Top)CC0 1.0ClarityLow-cost
Green Road/Inner Road JunctionCC0 1.0ClarityLow-cost
Above UnderpassCC0 1.0ClarityLow-cost
St Aubin's VillageCC0 1.0ClarityLow-cost
St Mary's VillageCC0 1.0ClarityLow-cost
Victoria Avenue EastCC0 1.0ClarityLow-cost
Gorey PierCC0 1.0ClarityLow-cost
St Ouen's VillageCC0 1.0ClarityLow-cost
St Peter's VillageCC0 1.0ClarityLow-cost
Red Houses/Route Orange JunctionCC0 1.0ClarityLow-cost
La Collette/Mount BinghamCC0 1.0ClarityLow-cost
Trinity VillageCC0 1.0ClarityLow-cost
Sion Village (Co-Op)CC0 1.0ClarityLow-cost
Queen's Road RoundaboutCC0 1.0ClarityLow-cost
Mont Millais/College Hill JunctionCC0 1.0ClarityLow-cost
Elizabeth Terminal - St Helier HarbourCC0 1.0ClarityLow-cost
St John's VillageCC0 1.0ClarityLow-cost
Longueville Road/Georgetown JunctionCC0 1.0ClarityLow-cost
La Moye SchoolCC0 1.0ClarityLow-cost
St Lawrence VillageCC0 1.0ClarityLow-cost
Georgetown JunctionCC0 1.0ClarityLow-cost
Broad St CC0 1.0ClarityLow-cost
Beresford Street (Calibration) New No 1CC0 1.0ClarityLow-cost
St Saviours Hill Guard houseCC0 1.0ClarityLow-cost
Howard Davis FarmCC0 1.0ClarityLow-cost
Gloucester StreetCC0 1.0ClarityLow-cost
Queens Round RoundaboutCC0 1.0ClarityLow-cost
helvetia school CC0 1.0ClarityLow-cost

No reference monitor here, so the value is the median of low-cost sensors (at least two reporting each hour). Low-cost sensors can read high in humid air. Data via OpenAQ; licences as listed. How we rank. Embed this on your site.

Updated 2026-10-01 06:07 UTC. Values are PM2.5 in µg/m³ (fine particles), the median of each city's monitors.