Heavy rain across interior Tamil Nadu, Karnataka; Krishnagiri and Dharmapuri see intense spell

Data from the Tamil Nadu government’s TN-SMART rainfall network showed substantial rainfall in Krishnagiri and Dharmapuri on September 20. Krishnagiri recorded 595.2 mm cumulatively across 16 rain gauges, averaging 37.2 mm, while Dharmapuri recorded 327.4 mm across nine stations, averaging 36.38 mm. Cuddalore, Kallakurichi, Ariyalur and Dindigul were among the other districts reporting significant rainfall during the period covered by the data.

India Meteorological Department (IMD) observations also recorded 38 mm of rainfall at Dharmapuri during the previous 24-hour observation period, while Salem received 5 mm and Tiruchirappalli 1 mm. Chennai's principal weather stations recorded no rainfall during that period.

The developing pattern is expected to keep several interior districts—including Salem, Namakkal, Krishnagiri, Dharmapuri, Tirupattur, Tiruvannamalai, Perambalur, Ariyalur, Vellore, Kallakurichi and Erode—under watch for further showers and thunderstorms.

Southern districts such as Madurai and Sivaganga could also receive rainfall, while parts of the delta region remain susceptible to showers.

Karnataka is similarly experiencing widespread weather activity. The IMD has issued heavy-rain and thunderstorm warnings for South Interior Karnataka, as well as the state's coastal and north-interior regions, for September 20–24.

In Bengaluru, the IMD recorded 16 mm of rainfall and forecast one or two spells of rain or thundershowers on September 20 and 21, with thunderstorms and lightning also possible.

While some weather observers have described September 20 as potentially one of Bengaluru's heavier rainfall days, that characterisation is best treated as a forecast assessment rather than a confirmed record.