Tirunelveli is situated on the banks of the only perennial river in Tamil Nadu, Tamirabarani, which divides the city into the Tirunelveli quarter and the Palayamkottai area. It is the sixth-largest city in Tamil Nadu and is a commercial hub in the region known for its administrative and educational services, and agricultural trading.

Tirunelveli city experiences a semi-arid climate with average temperatures reaching 39.4°C in the month of May and varying around 21.7°C during the winter months of January and February. The climate can become very hot in the months of April, May, and June with temperatures going as high as 42.5°C, however, upon the onset of South-West monsoon by early June, there is a drop in the temperature and by October, both day and night temperatures decline significantly.

The city is closer to the foothills of the Western Ghats, but is rain shadowed by the Agasthyamalai hills from South-West monsoon, therefore receives majority of its average annual rainfall of 680 mm during October to December months brought in by North-East monsoon winds.

In February 2020, Tirunelveli was selected as one of the project cities under Phase 2 of the CapaCITIES project and is being supported by the implementing agencies in development of Climate Resilient City Action Plan and implementation of Quick-win and co-financing projects.