Air pollution not only has serious impacts on public health, but also affects ecosystems and increases the impact of climate change. This study evaluated air quality at 13 locations (one base station (KK01) and 12 impact stations (KK02, KK03, KK04, KK05, KK06, KK07, KK08, KK11, KK12, KK14, KK19 and KK28)) belonging to eight districts, towns and cities in Hau Giang province with a frequency of six times/year (January, March, May, July, September, and November) with four replicates in each monitoring phase. Noise, total suspended particles (TSP), nitrogen dioxide (NO₂), sulfur dioxide (SO₂), carbon monoxide (CO) and hydrogen sulfide (H₂S) parameters are used to evaluate the quality of the air environment. Noise is compared with national technical regulations on noise (QCVN 26: 2010/BTNMT), H₂S is compared with national technical regulations on some hazardous substances in ambient air (QCVN 06: 2009/BTBMT), while the remaining indicators are evaluated using national technical regulations on ambient air quality (QCVN 05: 2013/BTNMT). Methods of cluster analysis (CA) and principal component analysis (PCA) are used to group air quality and main indicators affecting the quality of the air environment. Research results show that, the air environment in Hau Giang province in 2020 is mainly noise pollution. The criteria including TSP, NO₂, SO₂, CO and H₂S are within the permissible limits of current regulations. The PCA results show that 6 indicators selected for the initial monitoring all contribute to the impact on air quality in the area. Sources of air pollutants generated by vehicles in main traffic axes, centers, industrial activities, coal-making villages, gases generated from landfills, people's activities through cooking process. Analysis of CA according to the observed frequency shows that air quality is divided into two groups mainly due to TSP. The CA results by locations show that the choice of the base ambient air monitoring location is satisfactory because the base and impact monitoring points are classified into two distinct groups. Research results provide important information on environmental quality and the significance of the monitoring indicators selection.