refresh leaflet map: map container is already initialized

Before initializing map check for is the map is already initiated or not

var container = L.DomUtil.get('map');
      if(container != null){
        container._leaflet_id = null;
      }

Html:

<div id="weathermap"></div>

JavaScript:

function buildMap(lat,lon)  {
    document.getElementById('weathermap').innerHTML = "<div id='map' style='width: 100%; height: 100%;'></div>";
    var osmUrl = 'http://{s}.tile.openstreetmap.org/{z}/{x}/{y}.png',
                    osmAttribution = 'Map data © <a href="http://openstreetmap.org">OpenStreetMap</a> contributors,' +
                        ' <a href="http://creativecommons.org/licenses/by-sa/2.0/">CC-BY-SA</a>',
    osmLayer = new L.TileLayer(osmUrl, {maxZoom: 18, attribution: osmAttribution});
    var map = new L.Map('map');
    map.setView(new L.LatLng(lat,lon), 9 );
    map.addLayer(osmLayer);
    var validatorsLayer = new OsmJs.Weather.LeafletLayer({lang: 'en'});
    map.addLayer(validatorsLayer);
}

I use this:

document.getElementById('weathermap').innerHTML = "<div id='map' style='width: 100%; height: 100%;'></div>";

to reload content of div where render map.

Try map.remove(); before you try to reload the map. This removes the previous map element using Leaflet's library (instead of jquery's).

the best way

map.off();
map.remove();

You should add map.off(), it also works faster, and does not cause problems with the events