Chennai's unprecedented cold on Monday, January 11-12.
Deep depression weakens the Gulf of Mannar low-pressure system.
Globally driven La Niña, jet stream patterns push cool air southward.
Trend continues Monday; rain moves into interior TN.
Chennai residents experience an unprecedented cold spell on January 11-12, with temperatures plunging to 24-25.1°C, approximately 5°C below normal maximum temperatures of 29.5-29.7°C. This dramatic temperature drop has left residents reaching for hoodies, sweaters, and warm beverages for the first time in years, with social media flooded with posts comparing Chennai's weather to Bengaluru and hill stations like Ooty.
Deep Depression Creates Unusual Drizzle and Cloud Cover
The remnants of the deep depression system that previously affected Tamil Nadu have weakened into a low-pressure area near the Gulf of Mannar, creating dense clouds approaching Chennai. These clouds form drizzle bands that turn cold as they move landward, generating unusual wind chill and acceleration of heat loss, factors typically absent in Chennai's coastal climate. Weather bloggers attribute the sustained cold to persistent cloud cover and wind patterns, unusual for January in Chennai.
Global Weather Patterns Drive Rare South Indian Cold Spell
The Chennai climate anomaly is driven by larger atmospheric phenomena, including La Niña conditions and shifting jet stream patterns that push cooler, drier air southward across peninsular India. Nights dipping below 20°C are exceptionally rare for Chennai, representing part of a wider cold spell affecting southern hill stations, including Ooty and Munnar, which have recorded frost, and Bengaluru is experiencing dense fog and chilly mornings.
Weather Outlook: Temporary Relief Before Seasonal Transition
The cold trend is expected to continue through Monday with light-moderate rainfall moving into interior Tamil Nadu by Monday evening. A complete break from rain is anticipated on Wednesday. The actual winter season for Chennai is forecast to begin from Pongal (January 14-15) onwards, when night minimums are expected to dip further for the next 2-3 weeks, while afternoons return to warm conditions. This represents a natural seasonal transition rather than a prolonged cold spell.
