Highcharts - Weather Symbols Datetime series

HTML

<script src="https://code.highcharts.com/highcharts.js"></script>
<script src="https://code.highcharts.com/modules/exporting.js"></script>

<div id="container" style="min-width: 310px; height: 400px; margin: 0 auto"></div>

JavaScript

var file = 'https://staging-vending.lrsdedicated.com/dyn/_pictures/weather-icons/{windex}.svg';

$(function() {
  $('#container').highcharts({
    chart: {
      type: 'spline',
      events: {
        load: function() {
          var s = 0; // this.series.length;
          var series = this.series[s];
          for (var v = 0; v < series.points.length; v++) {
            var p = series.points[v];
            var f = file;
            f=f.replace(/\{windex\}/,p.y);
            p.y = 20;
            p.update({
              marker: {
                width: 40,
                height: 40,
                symbol: 'url(' + f + ')'
              }
            });
          }
        }
      }
    },
    title: {
      text: 'Monthly Average Temperature'
    },
    subtitle: {
      text: 'Source: WorldClimate.com'
    },
    xAxis: {
      type:"datetime"
    },
    yAxis: {
      title: {
        text: 'Temperature'
      },
      labels: {
        formatter: function() {
          return this.value + '°';
        }
      }
    },
    tooltip: {
      crosshairs: true
     },
    plotOptions: {
      spline: {
        marker: {
          radius: 4,
          lineColor: '#666666',
          lineWidth: 1
        }
      }
    },
    series: [{
      name: 'Weather symbol ',
      showInLegend: false,
      lineWidth: 0,
      data: [
      				[Date.UTC(2016,1,1),1],
      				[Date.UTC(2016,2,1),5],
      				[Date.UTC(2016,3,1),15],
      				[Date.UTC(2016,4,1),11],
      				[Date.UTC(2016,5,1),7],
      				[Date.UTC(2016,6,1),9]
            ]
    }, {
      name: 'London',
      marker: {
        symbol: 'diamond'
      },
      data: [
      				[Date.UTC(2016,1,1),1],
      				[Date.UTC(2016,2,1),2],
      				[Date.UTC(2016,3,1),5],
      				[Date.UTC(2016,4,1),14],
      				[Date.UTC(2016,5,1),16],
      				[Date.UTC(2016,6,1),18]
            ]
    }]
  });
});