Sikkim General Information
LOCATION
Sikkim is a very small hilly state in the Eastern Himalayas, extending approximately
114 Kms from north to south and 64Kms from east to west, surrounded by vast
stretches of Tibetan Plateau in the North, Chumbi Valley of Tibet and the kingdom
of Bhutan in the east, Darjeeling district of West Bengal in the south and the
kingdom in Nepal in the west . The state being a part of inner ranges of the
mountains of Himalayaa has no open valley and no plains but caried elevations
ranging from 300 to 8583 mtrs above means sea level consisting of lower hill,
middle and higher hills, alpine zones and snow bound land, the highest elevation
8583 mtrs. being the top of the Mt. Kangchendzonga itself.
TOTAL AREA STATEMENT
The total geographical area of the state is 7096 sq. Kms. but according to 1958-60
survey operation and the gazatteer fo Sikkim, the land area under different
utilization categories is 7299 sq. Kms. Detail break up as follow :
CLIMATE
The climate of the state has been roughly divided into the tropical, temperature
and alphine zones. For most of the period in a a year, the climate is cold and
humid as rainfall occurs in each month. The area experience a heavy rainfall
due to its proximity to the Bay of Bengal. The rainfall in north district is
comparatively less than of the other districts. The general trend of decrease
in temperature with increase in altitude holds good every where. Pre-monsoon
rain occurs in April-May and monsoon (south-west) operates normally from the
month of May and continues up to early October.
TEMPERATURE
The mean temperature in the lower altitudinal zone, it varies from 1.5 degree
centigrade to 9.5 degree centigrade. Temperature varies with altitude and slope.
The maximum temperature is recorded usually during July and August, and minimum
during December & January. Fog is a common feature in the entire state from
May to September. Biting cold is experienced at high altitude places in the
winter months and snowfall is also not uncommon during this period.
RAINFALL
An examination of availble rainfall date shows that the mean annual rainfall
is minimum at Thangu (82 mm.) and maximum at Gangtok (3494 mm.) . An isohyatal
analysis of these data reveals that there are two maximum rainfall areas (i)
South-East quadrant, including including Mangan, Singhik, Dikchu, Gangtok, Rongli
etc. (ii) South-West corner including Hilley . In between these two regions,
there is a low rainfall region e.g. Namchi. Rainfall in this area is about half
of that in the former areas. There is an area in the North-West Sikkim which
gets very little rainfall (even less than 4.9 mm.). This area is having mainly
snow -covered mountains. Rainfall is heavy and well distributed during the months
from May to early October. July is the wettest month in most of the places.
The intensity of rainfall during South-West monsoon season decreases from south
to North, while the ditribution of winter rainfall is in the opposite order.
The highest annual rainfall for the individual station may exceed 5000 mm. and
average number of rainy days ( days with rain of 2.5 mm. or more) ranges from
100 at Thangu to 184 at Gangtok.