The latitude and longitude of this town is 9°91’ N and 77°98’E respectively and the mean sea level (MSL) is 164.150m. The town is situated on the banks of river Gundar, a distributary of river Vaigai. The average maximum and minimum temperatures are of 39 °C and 27 °C. The town gets major rainfall during the south west monsoon period. The average annual rainfall being received in the town is 40.95 cm.
According to 2011 census, Thirumangalam had a population of 51,194 with a sex-ratio of 1,013 females for every 1,000 males, much above the national average of 929. A total of 4,952 were under the age of six, constituting 2,551 males and 2,401 females. Scheduled Castes and Scheduled Tribes accounted for 7.21% and .03% of the population respectively. The average literacy of the town was 81.91%, compared to the national average of 72.99%. The town had a total of 13564 households. There were a total of 19,212 workers, comprising 151 cultivators, 490 main agricultural labourers, 314 in house hold industries, 17,339 other workers, 918 marginal workers, 38 marginal cultivators, 44 marginal agricultural labourers, 44 marginal workers in household industries and 792 other marginal workers.
As per the religious census of 2011, Thirumangalam had 84.45% Hindus, 12.37% Muslims, 3.06% Christians, 0.02% Sikhs and 0.1% following other religions.
It is also known that the mangalyam for Lordess Meenakshi of Madurai was designed and made in Tirumangalam, so the name Tiru+Mangal(y)am came. In other way, it is said that when lord Murugan married Theivanai in Thiruparankundram (nearest to Tirumangalam), the "Tirumangalyam" was made here and hence the name came.
The Pathirakali Mariamman Temple located there was built in 1852, and the Devi at the Patrakali Amman temple is believed to be highly powerful. Every year, in the Tamil month of Vaikasi, a 13-day festival is celebrated, Vaikasi thiruvizha, along with daily deity procession and exhibitions. And also the Milk ice cream aka Paal Ice was prepared only at the occasion of Vaigasi Festival. Sri Cinnakatavarayan kamatchi Temple celebrates a festival at Mahasivarateri called parivetai. God Kamatchi amman in this temple. It was built in the 19th century.
Surrounding cultivate lands are the main places for the agricultural activities. Crops like cotton, ground nuts, chili peppers, cholam, ragi and kambu are cultivated here. The working population constitutes 31% of the total population. Nearly 24% of the population are engaged in business and related allied activities. Only 20% of the total workers are engaged in Primary Sector especially in Agriculture activities and the remaining 25% are daily labours.
Regular bus services are available from all important cities of Tamil Nadu and all the Buses from Southern part of the State passes through Tirumangalam. Frequent city bus facilities are available from Tirumangalam to Madurai, Usilampatti, Virudhunagar, Sholavandan and Vadipatti.
The government transport operates TNSTC buses and private travels operates semi sleeper buses such as PARVEEN, KPN everyday to Chennai. There are also private bus services such as Velmurugan transports, Sri Jaya Vilas Transport and Sri Balaji Roadlines operated on daily basis to all major cities.