Unprecedented Heat and the November Rain Outlook: Overview
(Dated: November 1, 2025)
Welcome to our detailed weather estimate for the beginning of November 2025! Today’s setup is highly unusual, presenting conditions that sometimes resemble the Southwest Monsoon period, yet with unique deviations. While we provide this personalized analysis, remember to follow the official advisories and information released by the Indian Meteorological Department (IMD) and government sources for authoritative updates.
The Current Atmospheric Dynamics: A Mixed Bag
Several major systems are influencing the weather across India today:
- Cyclonic Remnants and Wind Change: The remnants of the Mondha Cyclone (மோந்தா புயல்), which previously crossed Andhra Pradesh, are currently lingering in the region bordering Bihar and West Bengal, near the Himalayan foothills. This system is weakening rapidly and is expected to dissipate entirely into an atmospheric circulation within the next 12 to 24 hours. Crucially, the passage of this cyclone has already caused a wind change that is anticipated to persist for several days.
- Western Systems: The Depression is weakening in to low-pressure area in the Arabian Sea is projected to move inland toward Gujarat this afternoon and disappear within the next 24 to 36 hours. A dry high-pressure system is also circulating over areas like Delhi, Haryana, and Himachal Pradesh.
- Bay of Bengal Circulation: A circulation or low-pressure area has formed over the North Andaman Islands. However, this system lacks the support of tropical waves and westerly disturbances, meaning it is most likely to change course toward Myanmar or potentially West Bengal.
Despite the ongoing Northeast Monsoon season, the presence of this cyclonic circulation near the Northwest Bay of Bengal (North Head Bay) is expected to trigger a familiar pattern observed during the Southwest Monsoon: intense convective rain (வெப்பச்சலன மழை) over Tamil Nadu and Rayalaseema, particularly in North Tamil Nadu.
The Challenge of Heat: Broken Records
The immediate forecast for the next 24 hours suggests that dry weather will prevail across most parts of Tamil Nadu. Isolated light drizzle is possible only in parts of the Delta districts. Overall, the forecast points towards widespread dry weather across South India.
This period of dry weather is accompanied by unusually high temperatures. The presence of westerly winds will keep temperatures slightly below normal in West coastal areas, but inland Tamil Nadu will experience a significant spike in heat.
Temperature Extremes (November 1):
- North and Central Interior Tamil Nadu: Expected temperatures are 3 to 4°C above normal, reaching maximums of 35°C to 36°C.
- Chennai and Suburbs: Temperatures are forecast to be 2°C above normal.
- Central and Western Districts (e.g., Salem, Erode, Namakkal, Trichy, Dindigul): These areas may see temperatures 4 to 5°C above normal, with highs potentially reaching 37°C to 38.5°C. Similar conditions are expected in Southern coastal areas like Virudhunagar, Thoothukudi, and Nellai.
- Coastal residents can anticipate some relief when the sea breeze starts after 3:00 PM.
This heat is setting new records. Yesterday, Nungambakkam recorded 35.6°C (a first since 1999), and Meenambakkam recorded 35°C (a second time). Furthermore, Madurai recorded 37.5°C, marking the third occurrence of such high heat since 1999.
Why the Monsoon is Sluggish: The Suppression Phase
A primary reason for the recent lull in monsoon activity is the unfavorable positioning of tropical waves such as the MJO, Kelvin Wave, and Equatorial Rossby Wave. These waves were favorable in October, leading to an overall 35% increase in rain above average across Tamil Nadu.
Currently, we are in a suppression phase (indicated by a dark orange shade over the Bay of Bengal, the Indian Ocean, and South India). During this phase, conditions are unfavorable for the formation of circulations or favorable wind patterns, leading to the current delay in the monsoon.
November Long-Range Outlook
Looking ahead, based on the weekly RMM forecasts (while acknowledging that long-range predictions carry lower success chances):
| Week | Date Range (Approx.) | Conditions & Key Factors | Regional Rainfall Outlook |
|---|---|---|---|
| First Week | Early November | Dry weather. Isolated convective thunderstorms (வெப்பச்சலனமழை) likely starting from November 2nd or 3rd. | Dry across most of Tamil Nadu, Kerala, Karnataka. |
| Second Week | ~Nov 10 – Nov 13 | Arrival of Easterly Winds (கிழக்கு திசை காற்று). Monsoon rains expected to be moderate. | Above-normal rain projected for Interior Tamil Nadu, especially South and West. Coastal districts may see near-normal or slightly below-normal rain. |
| Third Week | Nov 17 – Nov 24 | Weak trough (ட்ராஃப்) structure near Delta and Gulf of Mannar, coupled with easterly winds. The current suppression phase is expected to end around the 13th or 14th. | Above-normal rain expected for most of Tamil Nadu, particularly South Tamil Nadu below the Delta region. North Tamil Nadu and Chennai expected to receive near-normal rain. |
| Fourth/Last Week | Late November | Tropical waves (MJO, Kelvin, Rossby) become favorable. A new MJO pulse is forecast to form in the Indian Ocean around November 18th or 19th. | Above-normal rain for Rayalaseema and North Tamil Nadu coastal areas, including Chennai. Interior and Delta regions likely to receive near-normal rain. |
The MS Rainman estimate gives a 60% probability of achieving near-normal rainfall for November, provided a few heavy rain episodes occur after November 15th, when conditions are expected to become more favorable. The remaining 40% probability suggests slightly below-normal rainfall.
24 Hrs Rainfall Probability : Mostly Dry Weather Expected in South India for next 24hrs except few isolated Light showers in Telangana and north interior KA Konkan.
(Note: This forecast is based on the data available for November 1, 2025. Stay safe and follow local authorities for real-time safety advisories.)
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