Tamil Nadu Weather: 41°C in Vellore; No Heatwave Alert Despite Rising Mercury

Tamil Nadu Weather: Even as temperatures climb across several parts of Tamil Nadu, the India Meteorological Department (IMD) has not issued a heatwave alert for the state, clarifying widespread public confusion over the terminology used in recent weather updates.

While large swathes of northern and central India - including states such as Madhya Pradesh, Uttar Pradesh, Rajasthan and Odisha - are bracing for severe heatwave conditions, Tamil Nadu does not currently meet the official criteria required for such a declaration.

Why No Heatwave in Tamil Nadu?

As per the IMD, a heatwave is declared only when at least two weather stations in a meteorological subdivision record temperatures 4.5°C above normal for two consecutive days. In Tamil Nadu, although temperatures have been high, the deviation from normal has largely remained within 2-3°C above average, falling short of the threshold.

Even Karur Paramathi - among the hottest locations in the state - has not crossed the required anomaly mark. Nationally, only a couple of stations such as Ratlam and Umaria in Madhya Pradesh have recorded anomalies exceeding 4.5°C so far.

Temperatures Across Tamil Nadu

Interior districts continue to sizzle, with Vellore recording the highest temperature in the state at 41.0°C on Sunday. Other key readings include:

Hill stations, as expected, remain significantly cooler, with Udhagamandalam at 27.4°C and Kodaikanal at a pleasant 22.1°C.

Weather Pattern and Rainfall Activity

The Regional Meteorological Centre noted very light rainfall in parts of southern Tamil Nadu, particularly Tirunelveli and Kanyakumari districts. Oothu in Tirunelveli recorded the highest rainfall at 6 mm, while most other regions remained dry.

Meteorologists attribute the current weather pattern to a trough or wind discontinuity extending from Telangana to the Comorin area, influencing conditions over interior Tamil Nadu.

Yellow Alert for Rain and Thunderstorms

Despite the absence of a heatwave warning, the IMD has issued a yellow alert for rainfall and thunderstorms.

• April 20-21: Light rain is expected at isolated locations, especially over Western Ghats districts, delta regions, and south coastal areas.
• Thunderstorms with lightning and gusty winds reaching 30-40 kmph may occur at one or two places.

However, the rest of the state is likely to experience largely dry weather.

Hot and Humid Conditions to Persist

A separate yellow alert for temperature highlights hot and humid conditions over coastal Tamil Nadu, Puducherry, and Karaikal from April 20 to April 24.

Maximum temperatures are expected to remain steady with a slight rising trend, particularly over interior districts. Coastal areas will continue to experience discomfort due to high humidity levels rather than extreme heat.

Chennai Weather Outlook

For Chennai, the forecast remains consistent over the next two days:

• Maximum temperature: 37-38°C
• Minimum temperature: Around 28°C
• Conditions: Partly cloudy skies with hot and humid weather

While Tamil Nadu is undoubtedly experiencing peak summer conditions, the absence of significant temperature anomalies means that no official heatwave has been declared. Instead, residents are likely to face a mix of rising heat, humidity, and occasional thunderstorms in the days ahead.

Authorities continue to advise caution, particularly during peak afternoon hours, as discomfort levels remain high despite the technical absence of a heatwave.