Hennebont Air Quality Index (AQI)

Loading live AQI data...

Loading weather snapshot...

Loading historical AQI trends...

Hennebont, nestled in the heart of Brittany (Bretagne), France, occupies a strategic position within the Blavet valley, approximately 5km inland from the Atlantic Ocean at the head of the estuary. The city’s terrain is gently undulating, rising slightly from the riverbanks, with an average elevation of around 20 meters. This proximity to the coast exerts a significant influence on its climate and, consequently, its air quality. The surrounding landscape is a mosaic of agricultural land – primarily dairy farming and cereal crops – interspersed with patches of woodland and the expanding urban areas of Lorient to the east. Historically, the Blavet valley supported a thriving industrial belt, focused on shipbuilding and fishing, though this has diversified in recent decades. The urban-rural gradient is relatively sharp, transitioning quickly from the denser built environment of Hennebont to the more open countryside. The prevailing winds, typically from the west and southwest, carry maritime air inland, which can both dilute pollutants and transport salt spray. However, these winds can also funnel pollutants from the Lorient industrial zone towards Hennebont, particularly during periods of stagnant atmospheric conditions. The river itself, while a vital transport link, can contribute to localised humidity and potential for fog formation, impacting pollutant dispersion.

Hennebont’s air quality follows a distinct seasonal pattern. Winter (December-February) often sees poorer air quality due to increased residential heating, particularly wood burning, combined with frequent temperature inversions trapping pollutants near the ground. Calm, damp conditions and fog exacerbate this, reducing dispersion. Spring (March-May) brings improvement as temperatures rise and winds become more frequent, flushing out accumulated pollutants. However, agricultural activities, like fertiliser application, can contribute to ammonia levels. Summer (June-August) generally offers the cleanest air, benefiting from strong Atlantic breezes and higher temperatures promoting pollutant dispersal. However, occasional heatwaves can lead to increased ozone formation. Autumn (September-November) is a transitional period. The return to heating, coupled with calmer weather and the start of agricultural waste burning, can lead to a gradual decline in air quality. Sensitive individuals – children, the elderly, and those with respiratory conditions – should be particularly cautious during winter and autumn months. Avoiding strenuous outdoor activity on still, cold days and monitoring local conditions is advisable. Periods of strong westerly winds in summer are generally favourable for outdoor pursuits. The maritime influence moderates extremes, but localised pollution events can still occur.