For most major urban centres in Uganda, air quality has been widely diverse during the first half of the year from sharp temporal spikes in February (up to 160 µg/m3) to cleaner air during the rainfall seasons of March, April and May.
Pollution variations over a 24-hour period conform to the same pattern throughout, with higher pollution levels from 05:00 to 9:00 (morning hours) and 18:00 to 23:00 (evening hours), while lower pollution levels occur between 10:00 and 16:00. This is largely due to meteorological influence, reinforced by daily outdoor activities patterns.
The highest daily averages were registered in February throughout the country up to over 6 times the WHO health guidelines of 25 µg/m3.
Average monthly levels varied between 16 µg/m3 for rural backgrounds to 67 µg/m3 for urban locations and lowest levels registered during the rainfall months of March, April and May.
The ongoing COVID-19 lockdown restrictions also seem to have had some contribution to pollution reduction due to reduced activities within Kampala. Early morning peaks in urban areas registering up to 36% drop from the levels experienced 3 weeks before imposed total lockdown. This is a similar case with 2020 where the city registered a reduction of 40% during the lockdown period.
Kampala areas continue to exhibit higher pollution levels and short-term variations still largely exceed the health guideline limits.
Pollution variations over a 24-hour period conform to the same pattern for all monitored areas with higher pollution levels from 05:00 to 9:00 (morning hours) and 18:00 to 23:00 (evening hours), while lower pollution levels occur between 10:00 and 16:00. This is largely due to meteorological influence, and daily outdoor activities patterns.
Average daily air quality levels were largely within the unhealthy zones for the 6-month period with only about 61 days within the WHO daily health guidelines, and 13 days with good air quality for a single urban background location in Kampala.
The month of February had the highest concentrations throughout monitored locations in Uganda with Kampala urban locations experiencing up to 160 µg/m3 (more than 6 times the WHO daily health guidelines) compared to 110.7 µg/m3 for urban locations outside Kampala.