Error using fread.. If i change the yearindex to 1 it can read but then the size of sic becomes 334*448*35, and gives error the number of rows are not equal.

clear all;clc;

% latitudes and longitudes and area elements for each grid cell
fid = fopen('psn25lats_v3.dat');
lat = fread(fid,[304,448],'int')./100000;
fclose(fid);
fid = fopen('psn25lons_v3.dat');
lon = fread(fid,[304,448],'int')./100000;
fclose(fid);
fid = fopen('psn25area_v3.dat');
area = fread(fid,[304,448],'int')./1000;
fclose(fid);
%
% path to data directory 
%
folderpath = 'C:\Users\SK\Documents\MATLAB\nsidc0051_daily\monthly';

% % months to process
months = [1 2 3 4 5 6 7 8 9 10 11 12]; %1:12;
% 
% % years to process
years = 1979:2012;
sic_avg_per_month = zeros(448,304,12);
sic_std_per_month = zeros(448,304,12);
sic_trend_per_month = zeros(448,304,12);
sic_year = zeros(304,448,34);

for mi = 1:12,
    yearindex = 0;  
     % allocate size per month with all years   
    for yi = years, 
            if mi<10,
                monthpath = strcat('0',num2str(mi));
            else
                monthpath = num2str(mi);
            end

              if (yi<=1987 && mi<=08),
                  filename_str = strcat( 'nt_',num2str(yi),monthpath,'_n07_v1.1_n.bin' );
              elseif (yi>=1987 && mi>08) && (yi<1992),
                  filename_str = strcat( 'nt_',num2str(yi),monthpath,'_f08_v1.1_n.bin' );
              elseif (yi>1991) && (yi<=1995 && mi<10),
                  filename_str = strcat( 'nt_',num2str(yi),monthpath,'_f11_v1.1_n.bin' );
              elseif (yi<=1995 && mi>=10),
                  filename_str = strcat( 'nt_',num2str(yi),monthpath,'_f17_v1.1_n.bin' );
              end

              fid = fopen(filename_str,'r');
              sic = fread(fid,[304 448],'int8');
              fclose(fid);
              sic(sic<0)=NaN; % remove land and pole
              yearindex = yearindex+1;
              sic_year(:,:,yearindex) = sic;

      end        
      sic_avg_per_month(:,:,mi) = rot90(mean(sic_year,3) ); % average
      sic_std_per_month(:,:,mi) = rot90(std(sic_year,0,3) ); % standard deviation

      for i=1:448,
          for j=1:304,
              if (sum(sic_year(j,i,:))== 0 || sum(isnan(sic_year(j,i,:)))>0), % has NaN
                  sic_trend_per_month(abs(i-449),j,mi) = NaN;
              else
                  stats = regstats(squeeze(sic_year(j,i,:)), [1979:2012]','linear',{'beta' 'rsquare' 'fstat'});
                  sic_trend_per_month(abs(i-449),j,mi) = stats.beta(2);
              end
          end
      end
   end

[Walter Roberson]

What is the error message you are getting with fread() ?

Are you sure it is "sic" that is becoming 334*448*35 and not "sic_year" ?