Rainfall data of May 2026 of some towns of Sub-Himalayan W Bengal (SHWB) and Sikkim.

May marks the final month of the pre-monsoon season and normally receives 257.5 mm rainfall over the Sub-Himalayan West Bengal (SHWB) and Sikkim region according to IMD (1971–2000 normals). The month is usually characterized by thunderstorms, squalls, hailstorms, and increasing moisture influx from the Bay of Bengal ahead of the southwest monsoon.

---

May 2026 was a highly variable month, with rainfall distributed unevenly across the region. Some locations experienced rainfall well above the long-term normal, while others remained comparatively dry.

A notable feature was the occurrence of several intense rainfall events between 13–17 May and again around 22–26 May, particularly affecting Sikkim and parts of the Himalayan foothills.
The extraordinary rainfall which took place in Kalimpong on 28May2026 is covered in an earlier blog.

 Wettest Stations

1. Mangan – 642.3 mm
2. Gangtok – 584.5 mm
3. Sevoke – 440.4 mm
4. Kurseong – 434.2 mm

Driest Stations

1. Khanitar – 92.4 mm
2. Darjeeling – 131.2 mm
3. Kalimpong – 213.0 mm 

Above and Below normals
The IMD normal rainfall for May over SHWB & Sikkim is 257.5 mm. 

Above Normal
Mangan (+149%)
Gangtok (+127%)
Sevoke (+71%)
Kurseong (+69%)
Banarhat (+43%)
Alipurduar (+43%)
Siliguri (+30%)
Damthang (+18%) 

Near Normal 
Neora (−8%) 

Below Normal 
Kalimpong (−17%)
Darjeeling (−49%)
Khanitar (−64%)

Spatial Distribution

Northern Sikkim (see map - Zone 1)

Mangan and Gangtok experienced exceptional rainfall. 

Foothills and the Dooars (see map - Zone 2)

Sevoke, Banarhat, Alipurduar and Siliguri all received abundant rainfall. The foothill belt was particularly active during thunderstorm episodes.

Darjeeling/Kalimpong Hills (see map - Zone 3)

Darjeeling itself was surprisingly dry compared with neighbouring Kurseong and Kalimpong. This highlights the highly localized nature of pre-monsoon convection and terrain-induced rainfall.

Praful Rao
SaveTheHills
savethehills@gmail.com
9475033744

Rainfall data of March/April 2026 of Sub-Himalayan W Bengal (SHWB) and Sikkim.

Despite the numerous Western Disturbances (WD) hitting the Western Himalayas during the winter of 2026, winter rains for us in the eastern end of the Himalayas were conspicuous by their absence. This was because WDs, which are responsible for our winter precipitation were tracking along higher latitudes or veering off towards the Tibetan plateau as they moved east (see satellite image above) as such never reached the Darjeeling-Sikkim Himalaya.

Forest fires in South Sikkim on 17Feb2026 due to extreme dry weather

In Kalimpong, we received our first storm and rains around mid - March 2026 but the Darjeeling-Kalimpong districts remained largely deficient in rain in Mar2026. 
Sikkim, however received far more rain in March and it is tabulated below:

Rainfall data day-wise for APRIL 2026 of some places in the Darjeeling and Sikkim Himalayas is shown below:

 

 

Location of rain gauge stations and rough zones of rainfall are shown:

Zone 1:  Sikkim, especially North Sikkim, received the heaviest rainfall
Among all areas in the SHWB–Sikkim, the highest precipitation occurred in North Sikkim (Mangan, Lachen, Lachung, Chungthang belt).
Zone 2. Plains of Dooars and Alipurduar were also very wet. The foothill districts of Alipurduar, Jalpaiguri, and the Dooars experienced substantial rainfall due to strong thunderstorm activity and moisture convergence.
Zone 3.  Darjeeling and Kalimpong hills were wet but comparatively less so Although rainfall was above normal, totals in Darjeeling and Kalimpong were generally lower than in North Sikkim and parts of the plains.
And in this region, Kurseong certainly always has the heaviest rainfall. The foothills of the Dooars ie Gorubathan and that belt also have intense thunderstorms and heavy rain.

Graphical Analysis of Rainfall and Windspeed of March and April 2026 of Kalimpong

Praful Rao
SaveTheHills
savethehills@gmail.com
9475033744

Rainfall data Jun2014

June2014 saw no major weather systems developing in the Bay of Bengal and the first two weeks of the month were hot with not much rainfall in Sub-Himalayan West Bengal (SWHB) and Sikkim.
The second half of June2014 however witnessed heavy showers in the entire region - thus Kalimpong, Darjeeling and Siliguri received around 90% of the month's rainfall between 15-30Jun2014 (see slides 2-3) and this placed the region in TRMM's potential landslide zone (slide 4)
No major landslides were reported even though a landslide fatality did occur in Sikkim.

Praful Rao,
Kalimpong,
Dist Darjeeling

Rainfall data Darjeeling district and N Sikkim - Jun2013

Jun2013 was extraordinary; it was the month of the "Himalayan Tsunami" when torrential rains over Uttarakhand and Himachal Pradesh in mid Jun2013, caused unprecedented loss of life and a disaster which the country is still trying to grapple with.
Whilst the rest of the country reported normal to excess rainfall, the north eastern states of India went deficient in rainfall. STH reported the formation of two low pressure areas in the Bay of Bengal, the first weather system eventually reaching the Uttarakhand region in mid Jun2013.
Also, two interesting facts observed in Jun2013 were :-

• The 24hr rainfall over Dehradun on 17Jun2013 (338mm) was more than the entire month's rainfall in Kalimpong for Jun2013.
• In the Darjeeling -Sikkim area, approximately half the month of June2013 was almost dry (less than 5mm rainfall).
  
  
  Praful Rao,
  Kalimpong,
  Dist Darjeeling.