Air pollution is one of the biggest problems raised by the modern life. Each year, thousands of people are affected by air pollution, and some even die of air pollution. In the cities, the times and places where air pollution is at its worst create problems for the people with health issues, affecting their quality of life. Therefore, it would be good for the measures to be taken to carry out air pollution studies on a regional basis and to determine the level of pollution based on certain factors such as traffic density, changes in pollution throughout the day, weather conditions, etc. This study aims to determine the changes in air quality throughout the day depending on the weather conditions and traffic density in various areas of Kastamonu city centre. In line with this purpose, we examined the changes in the particulate matter (in 3 different sizes) and CO2 concentrations of the air based on certain factors. The results show that the quality of air changes to a great extent depending on all the factors studied.