Thiruvallur area, a recently framed region bifurcated from the past Chengalpattu area (on first January 1997), is situated in the upper east some portion of Tamil Nadu. It lies in North scope somewhere in the range of 12°15′ and 13°15′ East longitude somewhere in the range of 79°15′ and 80°20′. It is limited on the north by Andhra Pradesh State, on the east by the Bay of Bengal, on the southeast by Chennai area, on the south by Kanchipuram and on the west by Vellore area.
The beach front area of the locale is for the most part level and inauspicious; yet in alternate parts it is undulating and even uneven in a few spots. The yearly precipitation ordinary (1970-2000) of Thiruvallur area is 1152mm. The yearly precipitation projection for the periods 2010-2040 (2020s), 2040-2070 (2050s) and 2070-2100 (2080s) show a general decline of 0.1%, 5.0% and 5.0% separately as for the pattern (1970 – 2000).