Monsoon Watch-- 5...29th May 2026

🟢 Vagaries Summary – Monsoon Watch 5

🟢 Pre-Monsoon Rainfall: Near Normal

🟢 May Heat: Near Normal and adequate for seasonal low development

🟢 Equatorial Winds: Strong and supportive for Monsoon progress

🟡 Pressure Gradient: Neutral, but expected to improve further during early June

🟡 IOD: Currently Neutral; possibility of turning Positive later, which could aid the Monsoon

🟢 ENSO: Still Neutral. A fully qualified El Niño is unlikely before August. Any significant impact of a stronger El Niño on India is more likely after September 2026.

🌧️ Overall Assessment: Current indicators remain broadly supportive of normal Monsoon onset and advancement across India.

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Detailed Note:👇

Monsoon Limit Today:

1.El Niño: characterized by a positive RONI greater than or equal to +0.5ºC. 

The most recent RONI value (February/Mar/April 2026) is -0.5ºC.

By historical standards, to be classified as a full-fledged El Niño or La Niña episode, these thresholds must be exceeded for a period of at least 5 consecutive overlapping 3-month seasons.

Proper qualified normal strength EL Nino not before August...

 ENSO Alert System Status: El Niño Watch ENSO-neutral conditions are present.

* Equatorial sea surface temperatures (SSTs) are near-to-above-average across the central and eastern Pacific Ocean. 

El Niño is likely to emerge soon (82% chance in May-July 2026) and continue through Northern Hemisphere winter 2026-27 (96% chance in December 2026 – February 2027).*

So, Effectively, the feared "strong Historical EL Nino" could affect India after September 2026.

2. I.O.D

3.Pre Monsoon Rainfall: Normal  

4.Pre Monsoon Heat: Normal 

MAY HEAT

5.Pressure Gradient: Neutral

6. Equatorial Winds : Strong

7.Vagaries' Estimate:

Dates of Onset up to Maharashtra.

Monsoon Onset over Kerala /N.E. States; 2nd June-4th June

Coastal Kar: 6th/7th June.

South Konkan/Goa: 8th/9th June

Monsoon Onset over Mumbai/Pune/ West Bengal: 12th/14th June...Pre Monsoon Showers 3rd June onwards.

South Interior Maharastra: 12th June.

North Interior Maharashtra /Marathwada: 15th/18th June.

{Surat/Bharuch/Valsad/Ahmedabad/Baroda: Light to moderate pre monsoon Showers/Thundershowers on 2nd/3rd/4th June. Monsoon after 16th/17th June in South Gujarat.}

 Monsoon Watch -5 on blog by 9.00 pm IST today

wit probable rainfall dates

Weather outlook from 28th May to 2nd June 2026.    

                          

(i) Mumbai Special 

(ii) Details:

*Kerala awaits SW Monsoon onset...

*North/Northwest regions to get some relief from heat

*Monsoon winds remain weak, with a weaker Somali jet, avoiding hitting Indian peninsula...sluggish progress after Andaman-Nicobar onset. 

850 hPa winds as of 27th May evening.

*The Madden-Julian Oscillation is in a convection-suppressing phase over the Indian Ocean (phases 6 and 7, with RMM amplitude >1), an important factor in the slow progression of the monsoon. 

The MJO is expected to weaken in magnitude in Phase 7 after 3rd June. Forecasts from various weather models show monsoon winds strengthening from June first week onwards. 

*Westerly winds will align over the southern Arabian Sea and are likely to reach a depth of up to 600 hPa around 3rd June (+/- 2 days). 

*This is when we expect monsoon onset over Kerala. 

*Further northward progress of the Monsoon seems to be on schedule as of now. 

We expect monsoon onset in Mumbai around 11th June (+/- 2 days). 

*A strong Western Disturbance (WD) will affect Northern States/UTs from 29th May, bringing dust storms followed by thunderstorms with gusty, damaging winds. 

Punjab, Haryana, Delhi NCR, Uttar Pradesh, Rajasthan and parts of Madhya Pradesh to receive rain/thunderstorms with damaging winds/lightning from 29th to 31st May. 

*The Himalayan region will get thunderstorms and hailstorms, and some snow at higher elevations.

WD trough will drop way south than normal, bringing in rain/thunderstorm chances for Gujarat and Southern Rajasthan during 29th to 31st May. 

27th May...

Clarification on this report in Times of India of 27th 

Contrary to some Agency reports, Mumbai Nights are NOT abnormally high this year...The facts and Normal Night Temperatures Line in red.👇.

Scurz

Colaba:

March:   Normal ..23       Actual  24.0

April       Normal..25.3     Actual 25.5

May:       Normal..27        Actual 27.7

 27th May 

This is Mumbai...Clean.

It is always the weather effect  on AQI

Ranked a far 73rd In the World ( Alarmist please note !)

Pics by Vagarian Hemant Merchant (from Walkeshwar)

Hype created and News Circulation by Foreign Agencies about Alleged "Indian Heat Waves"

The actual facts: Actual Fact shows Summer anomaly variations around+_ Degree only.👇

In this article the foreign scientist says pre-monsoon rain over large areas are below normal

 In reality 1-25 May: All india rain 5% above normal

Centrsl india: 23.7% above normal

South india: 19.4% above normal

North india: only 1.4% below normal

 Also avg temps across ~60% of country so far this May is below normal

The highest average may temp for India was in 1921 31.92c and northwest india avg max temp was 39.86c. This May 2026 is not even close to it to say it historic heat.

Forget 1921, even this May will not break 2024 record which is the hottest may in satellite record (since 1980) with avg. Maximum temperature in May 2024 was 31.08c and northwest india it was 38.36c

Thus, there is :NO MASSIVE HISTORICAL EVENT" with respect to summers/heating in this May

The above times article is completely wrong , nonscientific and the editor journalist should be held accountable for publising totally false stuffs.

Comment by Vagarian Dr.Vineet Kumar.

 24th May..

Mumbai 

Hot Night : The 4th hottest (May Month) night Temperature ever recorded at 29.9°c on 24th morning.

Compared with the Highest ever first three for the month of May. 👇

Compared with the Hottest ever first three nights for May. 

But, as yet this year, Mumbai Temperatures have been "OK.. near normal" 👇

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Outlook Upto 31st May:

Mumbai  

*Hot, humid, sweaty conditions as humidity increases to 85% and possibly a few light pre Monsoon showers ( more stuffy conditions).

*Temperatures in day at 34° ( real feel at 40°) - night Temperatures low at 28/29°. 

[Highest minimum record could jump to 3rd place] 

*Heavier pre Monsoon thundershowers will occur from 3rd June. Regular Monsoon expected by 11th/12th June. 

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Pune: 

Clouds gathering by late afternoon, and possible 50% chance of pre Monsoon thundershowers. 

Temperatures in the day 38° and 23/25°. 

Monsoon by 11th/12th June. 

Sambhajinagar will be hot at 42° and dry.

Vidharbh will be sizzling between 44 - 47° as, usual. Convective Thunderstorm expected around May end.