Rainfall:

IMD New High Spatial Resolution (0.25X0.25 degree) Long Period (1901-2022) Daily Gridded Rainfall Data Set Over India. This data product is a very high spatial resolution daily gridded rainfall data (0.25 x 0.25 degree). The unit of rainfall is in millimeter (mm). Data available for 122 years, 1901 to 2022. Data is arranged in 135x129 grid points. The first data in the record is at 6.5N & 66.5E, the second is at 6.5N & 66.75E, and so on. The last data record corresponds to 38.5N & 100.0E. The yearly data file consists of 365/366 records corresponding to non leap/ leap years.

Click here for sample Fortran code To read the data.

PROGRAM READ
PARAMETER(ISIZ=135,JSIZ=129)
DIMENSION RF(366,ISIZ,JSIZ)
OPEN(7,FILE='E:\DATA\ind1901_rfp25.GRD',
+ FORM='UNFORMATTED',ACCESS='DIRECT',RECL=ISIZ*JSIZ*4,
+ STATUS='OLD')
C TAKE NDAY=366 FOR LEAP YEARS
NDAY=365
DO IDAY=1,NDAY
READ(7,REC=IDAY)((RF(IDAY,I,J),I=1,ISIZ),J=1,JSIZ)
C The data on the grid is from South to North. i.e. J=1
C corresponds to lat. 6.5 N, J=2 corresponds to 6.75 N and so C on.
ENDDO
STOP
END

/* This program reads binary data for 365/366 days and writes in ascii file. */
#include
main()
{ float rf[135][129],rainfall;
float lo[135], la[129] ;
int i, j, k, year, year1, month, date, nd ;
FILE *fptr1,*fptr2;
int nd1[13] = {0,31,28,31,30,31,30,31,31,30,31,30,31} ;
int nd2[13] = {0,31,29,31,30,31,30,31,31,30,31,30,31} ;
year = 2013 ;
printf("Year = %d",year) ;
fptr1 = fopen("g:\\data\\ind2013_rfp25.grd","rb"); // input file
fptr2 = fopen("g:\\data\\ind2013_rfp25.prt","w");
if(fptr1==NULL) { printf("Can't open file"); return 0; }
if(fptr2==NULL) { printf("Can't open file"); return 0; }
for(j=0 ; j < 135 ; j++) lo[j] = 66.5 + j * 0.25 ;
for(j=0 ; j < 129 ; j++) la[j] = 6.5 + j * 0.25 ;
year1 = year / 4 ;
year1 = year1 * 4 ;
for(month=1 ; month < 13 ; month++)
{ nd = nd1[month] ;
if(year == year1)nd = nd2[month] ;
for(date=1 ; date <= nd ; date++)
{ fprintf(fptr2,"\n%02d%02d%04d",date,month,year);
for(j=0 ; j < 135 ; j++)fprintf(fptr2,"%7.2f",lo[j]) ;
for(i=0 ; i < 129 ; i++)
{ fprintf(fptr2,"\n%8.2f",la[i]) ;
for(j=0 ; j < 135 ; j++)
{ if(fread(&rainfall,sizeof(rainfall),1,fptr1) != 1) return 0 ;
rf[j][i] = rainfall ;
fprintf(fptr2,"%7.1f",rf[j][i] );
}
}
printf("%4d %02d %02d \n",year,month,date);
}
}
fclose(fptr1);
fclose(fptr2);
printf("Year = %d",year) ;
return 0;
} /* end of main */

DSET e:\ind1901_rfp25.grd
TITLE 0.25 degr analyzed grids
UNDEF -999.0
XDEF 135 LINEAR 66.5 0.25
YDEF 129 LINEAR 6.5 0.25
ZDEF 1 linear 1 1
* CHANGE TDEF TO 366 FOR LEAP YEARS
TDEF 365 LINEAR 1jan1901 1DY
VARS 1
rf 0 99 GRIDDED RAINFALL
ENDVARS

CITATION (for Rainfall 0.25 x 0.25):

Should you refer to our product in your paper/presentation, please cite Pai et al. (2014). Pai D.S., Latha Sridhar, Rajeevan M., Sreejith O.P., Satbhai N.S. and Mukhopadhyay B., 2014: Development of a new high spatial resolution (0.25° X 0.25°)Long period (1901-2010) daily gridded rainfall data set over India and its comparison with existing data sets over the region; MAUSAM, 65, 1(January 2014), pp1-18.