Exceedance Monitor
Exceedance Monitor
How often does Ghana's air quality exceed national and international health guidelines? Data from the last 90 days.
Ghana Std Days
1/90
days any sensor exceeded 35 µg/m³
Avg Exceedance
0.1%
avg % of sensors exceeding Ghana Std
Worst Day (90d)
10.4%
2026-09-18
WHO >50% Days
71/90
days majority of sensors exceeded WHO 15 µg/m³
Daily Ghana Standard Exceedance
% of sensors with 24h avg PM₂.₅ above 35 µg/m³ · last 90 days
90-Day AQI Calendar
Each square = one day, coloured by dominant AQI category
Harmattan vs Non-Harmattan
Average PM₂.₅ during and outside the dry season (Nov–Mar)
Harmattan Season (Nov–Mar)
39.5
µg/m³ avg PM₂.₅
2.6× WHO guideline
Non-Harmattan (Apr–Oct)
21.2
µg/m³ avg PM₂.₅
1.4× WHO guideline
Ghana Standard for PM₂.₅: 35 µg/m³ (24h average). WHO 2021 guideline: 15 µg/m³ (24h average). Updated 12:00 PM GMT.