A presentation made at Open Data Camp, Bangalore, on March 24, 2012. A part of the Know Your Climate initiative (knowyourclimate.org ) of Public Affairs Centre.

1. Climate Data in India:
Open and Closed
- Pavan Srinath
Environmental Governance Group, Public Affairs Centre
pavan.srinath@pacindia.org | @zeusisdead

2. Introduction
Public Affairs Centre is a non-profit organisation in Bangalore promoting good governance since 1994
through research, advocacy and action.
In 2010, we formed a new group called the Environmental Governance Group, focusing on trying to develop
governance solutions to environmental issues in India, including climate change adaptation.
In the struggle for assessing climate change impacts, exploring robust adaptation options, and trying to
work with both community knowledge & climate science, we thought that it was worthwhile to take a step
back, and try to learn more about our local climate first.
This started an initiative called Know Your Climate.
www.pacindia.org | www.knowyourclimate.org

3. Climate Data in India
• Indian Meteorological Department, the Hegemon
– Lots of data vs. No data available in the public domain.
The conundrum is that India has one of the oldest meteorological institutions in the world,
with a rich instrumental record, but very little data is available for the public to use!
• IMD Stations & Everybody else’s Rain Gauges
While IMD maintains weather stations across India, state economics departments, disaster
management cells and others maintain a far larger number of rain gauges across the country.
Some states like Rajasthan have put rain gauge data in the public domain (HT: India Water
Portal), but others are yet to follow.
• Station data vs. Gridded products vs. Satellite products
Station data can be really expensive! So, data from individual stations are usually processed
to develop gridded data sets, both in India and elsewhere. The IMD has developed a few that
are inexpensive, but with restrictions on use. There’s currently one daily gridded dataset from
Japan that’s available for public use! (see next page)
Now satellites like NASA’s TRMM can directly measure a host of weather & climate
parameters including surface temperature, rainfall, sea winds and more!
• The Intrepid farmer!
In the heavily contested area of good quality & open climate data, where you can’t always
trust the numbers, sometimes it’s the intrepid farmer with a private rain gauge who comes to
your rescue!

4. Gridded data from Japan!
The only long-term (1951-2007) daily rainfall data set that’s currently open for non-commercial use:
http://www.chikyu.ac.jp/
Krishnamurthi et al (2009)
APHRODITE Rainfall data set, Research Institute for Humanity and Nature, Japan

5. Mr. Vimal Kumar, a coffee planter from Wayanad who started collecting
rainfall data daily from April 1983, and hasn’t stopped since!

6. Gridded data from Japan!
Can’t we go local?
Pan-Indian climate & monsoon analyses cannot
take into account India’s immense geographic and
climatic diversity. It’s imperative that we go ‘local’
with our understanding. Let’s ask the question
“What do we know about Bangalore’s climate?”
rather than “What do we know about India’s
climate?”
With gridded data sets, we can begin doing that
in an inexpensive manner.
http://www.chikyu.ac.jp/
Krishnamurthi et al (2009)
APHRODITE Rainfall data set, Research Institute for Humanity and Nature, Japan

7. Going Local with Climate Data
Zooming in on Bangalore
The next few slides will look
at the little grid cell that
focuses on Bangalore. The
two pink dots represent the
city & HAL airport IMD
stations, the likely source for
generating the gridded data.
APHRODITE Rainfall data set, Research Institute for Humanity and Nature, Japan

8. The Joy of Daily Rainfall Data

9. The Joy of Daily Rainfall Data
Monthly Rainfall Profile of Bangalore (1951-2007)
This is the most common picture that you
see, when somebody talks about the ‘rainfall
180 profile’ of a place.
160 What you can tell from this is that Bangalore has 153.8
two seasons of rainfall, one summer and one 149.2
monsoon.
140
120
101.9
Rainfall (mm)
100
89.1
82.0
80
62.1
60 50.1
40 36.7
20 15.2
9.7
1.6 4.4
0
Source: APHRODITE Rainfall data set, Research Institute for Humanity and Nature, Japan

10. The Joy of Daily Rainfall Data
Monthly Rainfall Profile of Bangalore (1951-2007)
If the last graph is converted into mm/day, you
end up with this graph, showing the monthly
averages of how much rain fell on a ‘per day’
basis.
10
Monthly Average
8
Rainfall (mm/day)
6
4
2
0
1
Source: APHRODITE Rainfall data set, Research Institute for Humanity and Nature, Japan

11. The Joy of Daily Rainfall Data
Daily Rainfall Profile of Bangalore (1951-2007)
The daily averages show a completely different picture!
And our seasons don’t respect monthly boundaries. 
10
Monthly Average
Daily Rainfall
8
Rainfall (mm/day)
6
4
2
0
1
Source: APHRODITE Rainfall data set, Research Institute for Humanity and Nature, Japan

12. The Joy of Daily Rainfall Data
Daily Rainfall Profile of Bangalore (1951-2007)
10.0
Daily Rainfall
8.0
When Bangalore
rainfall really
Rainfall (mm/day)
picks up!
6.0
Onset of the
Summer rain monsoon
4.0
2.0
A recurring dry period in June!
0.0
1
Source: APHRODITE Rainfall data set, Research Institute for Humanity and Nature, Japan

13. The Joy of Daily Rainfall Data
Daily Rainfall Probability, Bangalore
100%
Chance of Rainfall on
any given day
80%
% Chance of Rainfall
60%
On any given day, assuming no other
knowledge, there’s never any certain rain in
Bangalore. Unlike some places on the coast and
40% elsewhere.
20%
0%
1
Chance of rain >= 2.5mm

14. The Joy of Daily Rainfall Data
Daily Rainfall Probability, Bangalore
100%
But the certainty of some 7 day
rain within a week is far
higher. 1 day
80%
% Probabiliy of Rainfall
60%
40%
20%
0%
Jan
Axis Title
Chance of rain >= 2.5mm

15. The Joy of Daily Rainfall Data
Daily Rainfall Profile of Bangalore (1951-2007)
10.0
Daily Rainfall
8.0
Rainfall (mm/day)
6.0
4.0
2.0
0.0
1

16. The Joy of Daily Rainfall Data
How much rain do we get, when it does rain?
20
Amount of Rainfall
per rainy day
15
Rainfall (mm/day)
10
5
0
1
Days such as those in Feb/Mar seem to correspond well to the adage: When it rains, it pours!

17. The Joy of Daily Rainfall Data
What’s the most it can rain in a day?
120
Maximum recorded
rainfall on any date
100
80
Rainfall (mm/day)
60
40
20
0
1
We can get heavy rainfall in Bangalore almost any time between April and December. And Bangalore
gets ~1-2 heavy rainfall days almost every year. So why do they still catch us by surprise?

18. The Depressing part about Rainfall
Rainfall in Aug-Sept 2011, Bangalore
This is actual rainfall by day in 2011. On August
16 night, it rained very heavily, with the
Bangalore city weather station (near Maharani’s
college) recording over 100mm of rain.
http://www.imdaws.com/ViewAwsData.aspx

19. The Depressing part about Rainfall
What happens to Bangalore when it rains…
Boy drowns in a (Taken from news clippings)
drain Storm Drains
overflowing
Flooding of houses Trees uprooted
Gali Anjaneya
Severe Flooding in Hebbal
temple &
surroundings
damaged
2 die in mud cave-
in
----------------------------------------------------Traffic Disruptions-------------------------------------------------
http://www.imdaws.com/ViewAwsData.aspx

20. The Depressing part about Rainfall
What happens to Bangalore when it rains…
(Taken from news clippings)
Boy drowns in a Storm Drains
drain overflowing
Flooding of houses Trees uprooted
Gali Anjaneya
Severe Flooding in Hebbal
temple &
surroundings
damaged What has JnNURM done for us?
Water gushes
under the metro
Storm Water Drain irregularities
discovered.
BBMP starts fixing
More metro woes potholes 2 die in mud cave-
----------------------------------------------------Traffic Disruptions-------------------------------------------------
in

21. Revisiting traditional knowledge systems
The Malayalam calendar & Rainfall in Wayanad
If we can map rainfall patterns onto the traditional
Karkkidakam
calendar, it would go a long way in mainstreaming
traditional knowledge! This is just an example from what we
did in
Wayanad, Kerala.
Chinga masam
Edavam paadhi
Tulavarsham
Puthu mazha
Vishu Onam
Kumbha mazha
Harvest
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Kumar and Srinath, Climate Trends in Wayanad: Voices from the Community (2011)

22. A year’s rainfall is like a signature – each one unique.
Monthly Rainfall series in Wayanad, 2000-2011
1000
Muttil
800
Rainfall (mm)
600
400
200
0
2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012
Year
Just to throw a note of caution: the presentation discusses rainfall patterns and daily averages, but it’s good to remember
that they’re just that: Averages. Each year’s climate & rainfall pattern is still quite unique, as seen in the graph above.

23. Acknowledgements
All that you have seen is a part of the fledgling Know your climate initiative, where we
want people to understand their local climate using data that we help visualize. It’s not
yet operational, and we are looking for volunteers to help us out with web-designing
and visualization! Please spread the word! 
People who’ve helped make this possible are Adarsh DK and Yashas MS (Btech 2nd
year, NIT Surathkal), who spent summer ’11 working with us; Danesh Kumar, RASTA, for
the work in Wayanad; my colleagues at Public Affairs Centre: Jangal Jayaram, Prarthana
Rao, Kuldip Gyaneswar and Director R. Suresh.

24. References
APHRODITE Daily Rainfall Data set at the Research Institute for Humanity and
Nature, Japan: http://www.chikyu.ac.jp/
“Climate Trends in Wayanad: Voices from the Community”, Conference paper
(2011): http://goo.gl/QIA7k
IMD Automater Weather Station website:
http://www.imdaws.com/ViewAwsData.aspx
Do keep an eye on blog.knowyourclimate.org! 

25. Thank you!
www.pacindia.org @zeusisdead
greengovernance.wordpress.com pavan.srinath@pacindia.org