IITM Subdivision Dataset

The IITM Subdivision dataset is here. Users must follow the data use guidelines and restrictions of the IITM stated below. The following is a subset of the documentation provided by the IITM. Please refer to the IITM data website for additional information.

Note that the lat/lon coordinates of each "station" approximate the center of each subdivision. An image of the IITM subdivision boundaries can be found here.

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This document was last updated on December 9, 2003.

Copy Right:

Indian Institute of Tropical Meteorology (IITM)
Homi Bhabha Road
Pune 411 008, India

The accompanying data as described below may be freely used and
redistributed for non-profit and non-commercial research purposes,
provided IITM is duly acknowledged as the data source. Any
redistribution should necessarily include this document.


IITM Indian regional/subdivisional Monthly Rainfall data set


D.A. Mooley
B. Parthasarathy
K. Rupa Kumar
N.A. Sontakke
A.A. Munot
D.R. Kothawale

Primary Data Source:

India Meteorological Department

Data Period:


Network of rain-gauge stations:

While selecting the network of rain-gauge stations, an
effort was made to select a network which would provide one
representative station per district having a reliable record
for the longest possible period. The network selected under
these constraints consist of 306 almost uniformly distributed
stations for which rainfall data are available from 1871. The
hilly regions consisting of four meteorological subdivisions
of India which are parallel to Himalayan mountain range have
not been considered in view of the meagre rain-gauge network
and low areal representation of a rain-gauge in a hilly area.
Two island subdivisions far away from mainland have also not
been included. Thus, the contiguous area having network of 306
stations over 29 meteorological subdivisions measures about
2,880,000 sq.km., which is about 90 percent of the total area
of the country.

Preparation of Subdivisional/Regional rainfall series

The monthly (January - December) area weighted rainfall
series for each of the 29 meteorological subdivisions have
been prepared by assigning the district area as the weight for
each rain-gauge station in that subdivision. Similarly assigning
the subdivision area as the weight to each of the subdivisions in
the region, area weighted monthly rainfall series are prepared for
Homogeneous regions of India as well as for all India.


The data for the recent period 1991-2001 are preliminary estimates
based on the subdivisional means supplied by the India Meteorlogical
Department (IMD), which are in turn based on a variable network.
However, the IMD data have been rescaled to conform to the long-term
means of the respective subdivisions in the IITM-IMR data set. These
data will be updated as and when the full set of data for 306 stations
becomes available.

Key References

Mooley, D. A., Parthasarathy, B., Sontakke, N. A., and Munot, A. A 1981 : Annual rain-water over India, its variability and impact on the economy. J. Climatol, 1, 167-186.

Parthasarathy, B., Sontakke, N. A., Munot, A. A. and Kothawale, D. R. 1987: Droughts/floods in the summer monsoon rainfall season over different meteorological subdivisions of India for the period 1871-1984. J. Climatol, 7, 57-70.

Parthasarathy, B., Rupa Kumar, K and Munot, A. A. 1993 : Homogeneous Indian Monsoon Rainfall : variability and prediction. Proc. Indian Acad. Sci. (Earth Planet. Sci.) 121-155.

Parthasarathy B., Munot A.A., Kothawale D.R., 1995. All India monthly and seasonal rainfall series : 1871-1993. Theor. and Appl. Climatol., 49, 217-224.

Parthasarathy B., Munot A.A., Kothawale D.R., 1995. Monthly and seasonal rainfall series for all-India homogeneous regions and meteorological subdivisions : 1871-1994. Research Report No. RR-065, Indian Institute of Tropical Meteorology, Pune, 113pp.

Pant, G.B. and Rupa Kumar, K., 1997. Climates of South Asia. John Wiley & Sons, Chichester, 320 pp.


Please direct questions/problems and requests for updates to

Dr. Rupa Kumar Kolli
Scientist-E & Head
Climatology & Hydrometeorology Division
Indian Institute of Tropical Meteorology
Homi Bhabha Road
Pune 411 008, India

email: kolli@tropmet.res.in
Phone: +91-20-589-3600 Ext. 351
Fax: +91-20-589-3825