Finding out the present indoor air quality (IAQ) conditions in the Federal College of Agriculture, Akure (FECA) library within Nigeria is the aim of the investigation described in this piece. A reading room lacking a cooling system was used for the assessment. Before use, the sensor was collocated with a reference monitor at the National Agency for New Technologies, Energy and Environment (ENEA) reference station in Italy to confirm its accuracy. Temperature, relative humidity (RH), CO2, PM1, PM2.5, PM10, NO2, O3, and other concentrations were among the many internal thermal conditions found in the library room, according to the results. Temperature (28.4-36.30 oC), RH (47.7-67.80%), PM1 (0-80 µg/m3), PM2.5 (0-103 µg/m3), PM10 (0-106 µg/m3), NO2 (153-276 ppb), O3 (24-78 ppb), and CO2 concentrations ranged from 453 to 6158.1 ppm. The PM levels did not meet the guidelines set forth by the National Environmental Standards and Regulations Enforcement Agency (NESREA) and the World Health Organization (WHO). The results show a relationship between the PM and meteorological conditions. The location's CO2 and NO2 have a somewhat negative connection (r = -0.061, p = 0.000). The major component (PC1) has comparable loadings for PM1, PM2.5, and PM10, suggesting that all particle sizes contribute equally to variations in indoor air quality. Although it is encouraging to see that the contaminants do not pose a risk to users of libraries, all stakeholders should make sure that every effort is made to minimize their effects on people and library materials.