MATLAB: Plotting from an array at an interval

array indexingfor loopMATLABplotting

I am trying to plot two columns in an array. The x-axis represents months in the year and the y-axis is temperature values from each month. This data loops in my array in intervals of 12. I am trying to plot each year ( 12 months) as a seperate line on the plot. How can i do this?
My current code plots this as one line thorughout my plot.
for a = 1:length(skrar) 
    figure; 
    LH = load(skrar(a).name); 
    uni = unique(LH(:,2));
            plot(LH(:,3),LH(:,4),'Color',rand(1,3));
                title(LH(1,1) + " Median " + LH(1,2) + " til " + LH(end,2))
                manudir = {'Jan';'Feb';'Mar';'Apr';'Maí';'Jún';'Júl';'Ágú';'Sep';'Okt';'Nóv';'Des'};
                set(gca,'xtick',[1:12],'xticklabel',manudir)
                ylabel('Hitastig[°C]')
end
An example of my data looks like this:
422	1882	 1	-0.8	4
422	1882	 2	-5.8	4
422	1882	 3	-5.5	4
422	1882	 4	-3.1	4
422	1882	 5	 2.0	4
422	1882	 6	 4.5	4
422	1882	 7	 6.1	4
422	1882	 8	 4.1	4
422	1882	 9	 5.3	4
422	1882	10	 5.0	4
422	1882	11	-1.8	4
422	1882	12	-3.9	4
422	1883	 1	-1.4	4
422	1883	 2	-0.8	4
422	1883	 3	-2.9	4
422	1883	 4	 3.0	4
422	1883	 5	 1.9	4
422	1883	 6	 8.9	4
422	1883	 7	10.1	4
422	1883	 8	 7.7	4
422	1883	 9	 7.2	4
422	1883	10	 2.9	4
422	1883	11	-0.2	4
422	1883	12	-1.0	4
Column 3 is the months and column 4 is the temperature
My current plot looks like this:

Best Answer

There are likely any number of ways to do this.
One relatively straightforward way: 
ExData = [422	1882	 1	-0.8	4
          422	1882	 2	-5.8	4
          422	1882	 3	-5.5	4
          422	1882	 4	-3.1	4
          422	1882	 5	 2.0	4
          422	1882	 6	 4.5	4
          422	1882	 7	 6.1	4
          422	1882	 8	 4.1	4
          422	1882	 9	 5.3	4
          422	1882	10	 5.0	4
          422	1882	11	-1.8	4
          422	1882	12	-3.9	4
          422	1883	 1	-1.4	4
          422	1883	 2	-0.8	4
          422	1883	 3	-2.9	4
          422	1883	 4	 3.0	4
          422	1883	 5	 1.9	4
          422	1883	 6	 8.9	4
          422	1883	 7	10.1	4
          422	1883	 8	 7.7	4
          422	1883	 9	 7.2	4
          422	1883	10	 2.9	4
          422	1883	11	-0.2	4
          422	1883	12	-1.0	4];
[Yu,~,ix] = unique(ExData(:,2)); 
Mnthc = accumarray(ix, ExData(:,4), [], @(x){x});
Mnthm = cell2mat(Mnthc.');
figure
plot(1:12, Mnthm)
manudir = {'Jan';'Feb';'Mar';'Apr';'Maí';'Jún';'Júl';'Ágú';'Sep';'Okt';'Nóv';'Des'};
set(gca,'xtick',[1:12],'xticklabel',manudir)
.
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