Accepted answer

From your code it appears that your months are in thead and not tbody. So you should be really using $('thead th') selector. I would also recommend using the :parent selector to filter out empty ths

$('thead th:parent', table).each( function(i) {
    var month=$(this).text();

Also, your series data needs to be changed if you want the x-axis to be months, you should now have only 3 series, instead of the earlier 6. And each series will now have 6 points (one for each month) instead of previous 3 points/series. So your table parsing would need to change to something like this.

options.series = [];
$('tbody tr', table).each(function (i) {
    var tr = this;
    var serie = {}; = $('th', tr).text(); = [];
    $('td', tr).each(function (j) {;

Demo @ jsFiddle

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