Extreme rainfall event in Kalimpong town on 28May2026 (instant rainfall intensity > 500mm/hr)

Flooded street in Kalimpong town at around 04.15pm/28May2026 
 

 Meteorological conditions and warnings for what started OFF as a perfectly normal day
 I checked IMD forecasts, warnings and satellite imagery as I normally do each morning and found it was perfectly normal, in fact there was a slight improvement from a day earlier. There was a YELLOW warning for thunderstorm in place but that is more or less the norm through out this part of the year, for this region:

Extracts from IMD Midday Weather Bulletin for 28May2026 issued by RMC, Kolkata

 

Infra -Red (IR) Satellite Imagery of 28May2026 afternoon period

Satellite image of 12.15pm which shows no major convective buildup around Kalimpong, even though there were clouds west of us, in Nepal. 
It was around this time that we had the first burst of rainfall - which I reported on 'Hazard Alerts' our WhatsApp group. A member of the group, quipped that 'there was no rain even in Kalimpong town' which is about a km away from my home - so all in all it was perhaps just a very localized shower. Excerpt of my post is below:

The rainfall returned at around 3.45pm,and this time it was serious, with intense thunder, heavy rainfall and hail at places. Excerpt of my post is below:

Satellite image of 4.15pm (below) shows an increase in clouding especially in Nepal but still does not have the 'WHITE' clouds (in IR imagery) associated with intense cumulonimbus buildups and strangely, only Kalimpong had intense thundershowers whereas there was little rain over the other neighboring hill towns. The fact that it was very localized is borne out by the fact that there was no formal RED warning from IMD or the SACHET app.

The second burst of rain turned out to be certainly the most intense rainfall I have ever experienced - luckily, like most thunderstorms, it moved towards a NE direction after sometime and rainfall decreased. 

Placed above are the rainfall and wind charts which I have downloaded from the SaveTheHills Davis Vantage Pro2 AWS which is installed at my home.
The salient findings about the thunderstorm from the above chart are:
a. We had 82.8mm of rainfall in approx one and half hours.
b. Max (instantaneous) intensity of rainfall exceeded 500mm/hr

 

24hr Rainfall (in mm) data of 28May2026 (IMD):
On 28May2026,there was no major weather system which gave Kalimpong this rainfall, rather it was an isolated cell which gave us this very localized rainfall and therein lies the danger - such weather is very difficult to forecast and difficult to detect in satellite imagery.

Kalimpong 79.2; Siliguri 40.5; Darjeeling 1.2; Pedong 2; Gangtok 2.1; Mangan 0
  

Damage/Casualties
As per the information available to me, except for damage to electric poles at places and a number of trees which were uprooted, there has not been any major damage to lives or property due to yesterday's extreme rainfall event.
This maybe due to the fact that in May2026, Kalimpong has had only 125.2mm of rain prior to yesterday's deluge and that we had only 9mm of rain in the last week.
Lucky us.

Verified video

Location: Next to Kodamull building, RCM Road Kalimpong

Need of the hour: Cleaning, maintenance, and upgradation of the drainage system.

If Kalimpong — or any mountain town — is to withstand such torrential volumes of storm water, we must urgently address the condition of our drainage infrastructure. Existing drains need regular cleaning and maintenance, while the entire system requires systematic upgradation to cope with increasingly intense rainfall events.

Photo video credits: Naresh Changia, Kalimpong

Praful Rao
SaveTheHills
savethehills@gmail.com
9475033744 

(Lack of) Rainfall Data of March 2025 of some towns in Darjeeling - Sikkim Himalaya

 

All data from IMD

 

Sikkim, particularly North Sikkim, typically receives more winter and pre-monsoon precipitation than Darjeeling and Kalimpong districts. This is largely due to western disturbances that the reach higher latitudes, bypassing Darjeeling and Kalimpong.
However, this year, the Darjeeling and Kalimpong districts also experienced an unusual lack of significant pre-monsoon thunderstorm activity. The absence of moisture incursion from the Bay of Bengal contributed to this anomaly.
The resulting dry weather in the lower latitudes has led to severe water shortages in Darjeeling and Kalimpong, coinciding with peak tourist season. Furthermore, the dry conditions have caused numerous forest fires along the Teesta Valley, generating pollution and haze due to smoke.

Drone image of a forest fire in the Teesta Valley (in Sikkim, NE of Melli town) on 04Apr2025 at  9.20pm. These fires are a daily happening all along the valley where tinder dry vegetation catches fire or is set on fire.

The reason why we have not published rainfall data after Oct2024 is that in the ensuing drought like condition, there was absolutely no rainfall and as such no data to publish. Unfortunately, this is becoming the trend in our precipitation pattern.

Praful Rao
SaveTheHills
savethehills@gmail.com
9475033744

The sudden and heavy downpour of 17Jun2023 in Kalimpong.

Kalimpong experienced its first really heavy, showers in a thunderstorm which lasted for almost 90min from 7.00pm on 17Jun2023.
I checked the IR imagery and lightning at 5.30pm on 17Jun with a group of IIT (Mandi) interns and mentioned to them we had no lightning nor convective clouds in our vicinity. There was absolutely no indication that a severe thunderstorm was building up and the NOWCAST warnings for heavy rain also do not indicate this.

The timeline of satellite images below indicate how CB clouds developed and moved eastwards over Kalimpong from the hills of Nepal.

The rainfall intensity graph from the DAVIS AWS at my home shows that we had heavy rain (ie above 40mm/hr) for an hour at least and that we received almost 60mm of rain during this period.

Videos sent to our WhatsApp group by members show the severity of the downpour in Kalimpong on 17Jun2023 evening.         

                           

Update on 19Jun2023

My thanks to HA Members who shared the videos.

We had 101mm of rain in the last 24hrs (all of it from approx 7pm last evening till 4am on 18Jun2023)

Praful Rao
Kalimpong district
Darjeeling-Sikkim Himalaya
savethehills@gmail.com
9475033744

First significant rain in the hills on 16Apr2021 after Oct 2020 and a lightning strike.

 The entire Darjeeling - Sikkim Himalaya (with the exception of north Sikkim perhaps) has been virtually bone dry since the SW monsoons withdrew from our region in Oct 2020 and it was welcome when we had rains yesterday. The thundershowers showers started in the afternoon at various places but by late evening it was over the entire region and continued well into the night with high winds, thunder and lightning. IR cloud imagery of the day is shown:

Rainfall data of the region (in mm) for yesterday is given below:
Gangtok 88, Pakyong 58, Cooch Behar 29.7, Kalimpong 25, Darjeeling 17.2, Siliguri 10.4 Mangan 8.4.
A lightning strike took place at Hanuman Mandir, Delo in Kalimpong

Widespread hail was also observed through out the region and it made parts of Gangtok look like Norway during Christmas time. (MG Marg Gangtok is seen below)

Praful Rao
Kalimpong district
Darjeeling-Sikkim Himalaya

The New Normal: Extreme Rain (19/20Aug - Kalimpong)

 This image was posted in 'HAZARD ALERTS' our WhatsApp group at around 8.15pm on 19Aug2020

 

Other places of damage

• Topkhana (near CST - ward no 7)
• Upper Gairigaon (Painyun), Algarah.
• Soureni (near Algarah)
  
  

My thanks to all who contributed with the photos and information.

Praful Rao
Kalimpong district
Darjeeling - Sikkim

Super Cyclone Amphan makes landfall in the vicinity of Kolkata: 20May2020 (1430hrs onwards)

Source:https://en.allmetsat.com/metar-taf/india-nepal-bhutan-bangladesh-burma.php?icao=VECC

Tracking the Beast

Was declared a Cyclonic Storm 'Amphan' on 16May2020, after which it rapidly intensified in Severe Cyclone. STH posted continuous updates on the tracks of the storm

RSMC, Delhi and JTWC issued some 33 advisory bulletins and 18 warnings respectively from 15May until the storm made landfall exactly as predicted on 20May near Kolkata

First track forecast and the final track observed are placed below:

Rainfall

Fact Sheet:

·        * Landfall process started at around 1430hrs/20May2020 between Digha and Hadia islands as predicted and passed thru the Sunderbans between 1530hrs to 1730hrs.

·       *  Wind speed at the time of landfall and crossing coast 155kmph and going up to 185kmph in gusts. Max recorded windspeed in Kolkata, from observatory at Dum Dum was 130kmph at 1855hrs on 20May.

·        * Windspeeds in Kolkata started increasing from around 1700hrs, max windspeeds were around 1900-1920hrs after which the speeds became less. Max winds were felt between 17-2100hrs.
* Approx 5000 trees uprooted by the storm.

·        * Most impacts on South 24 Parganas and East Midnapur and then Kolkata, Howrah and Hooghly districts.

·        * Was tracked continuously by DWR along the East Coasts which could give accurate information on intensity, landfall point and time, associated weather, storm surge, heavy rain and winds at different districts.

·       *  Heavy to extremely rain was observed in all the affected areas. 24 hrs rain in Kolktata (Alipore) 240mm, Dum Dum 200mm.

·       * After hitting Kolkata, the storm moved in a NNE direction and crossed the Bangladesh border at 2330hrs and became a deep depression in Bangladesh on 21May2020.

·       * Windspeeds in Meghalaya were 60kmph on 21May2020 and affected the NE States thereafter.
    
 STH cautionary advice (printed by media days prior to the storm):

 Images from the SUNDERBANS

   

   

           Praful Rao
     Kalimpong district
     Darjeeling - Sikkim Himalaya

Death in the Mountains (09May2017)

A thunderstorm in the morning of 09May2017 struck a huge region as can be seen in the satellite image below. In the Darjeeling-Sikkim region, the rainfall was not intense during the storm but associated winds at around 0900hrs IST, knocked down several trees on National Highway10 (NH10) which links Siliguri with Gangtok .
One of the trees crashed directly onto the driver's cabin of a truck plying on the highway at Melli, killing him instantly.
This is first death due to hydro-meteorological causes in the Darjeeling-Sikkim Himalaya in 2017.

Rainfall at Kalimpong on 09May2017: 24mm

Praful Rao,
Kalimpong district
Darjeeling -Sikkim Himalayas