Cool. Thanks!! Works well.

Can we mount plugins yet? I see we can open an airport from path.

@rittels
Thanks again for the JS code which has helped me well until here.
(And in addition I discovered the GeoHash system ;p)

Also recommend to check following topic: https://community.windy.com/topic/77/windy-com-url-parameters

That happens, because the max resolution of the alphanum code is 0.01deg, thus 36 seconds (about 1km).

made code a bit shorter:

function createCoordCode(coords){
    let ar=[];
    for (let i=98;i < 123;i++)ar.push(String.fromCharCode(i));
    for (let i=65;i < 91;i++)ar.push(String.fromCharCode(i));
    for (let i=0;i < 9;i++)ar.push(i);

    let lat=Math.round(100*(coords.lat+90));
    let lon=Math.round(100*(coords.lon+180));

    return "m:"
            +ar[Math.floor(lat/3600)]
            +ar[Math.floor((lat%3600)/60)]
            +ar[lat%60]+"a"
            +ar[Math.floor(lon/3600)]
            +ar[Math.floor((lon%3600)/60)]
            +ar[lon%60];
}
console.log(createCoordCode({lat:38,lon:-30}));

JS function for you:

function createCoordCode(coords){
    let ar=[];
    for (let i=98; i < 123; i++) ar.push(String.fromCharCode(i));
    for (let i=65; i < 91; i++) ar.push(String.fromCharCode(i));
    for (let i=0; i < 9; i++) ar.push(i);

    let lat=Math.round(100*(coords.lat+90));
    let lon=Math.round(100*(coords.lon+180));

    lt1=Math.floor(lat/3600);
    lt2=Math.floor((lat-lt1*3600)/60);
    lt3=lat-lt1*3600-lt2*60;

    ln1=Math.floor(lon/3600);
    ln2=Math.floor((lon-ln1*3600)/60);
    ln3=lon-ln1*3600-ln2*60;

    return "m:"+ar[lt1]+ar[lt2]+ar[lt3]+"a"+ar[ln1]+ar[ln2]+ar[ln3];
}

console.log(createCoordCode({lat:-29,lon:100}));

Seems to be alphanumeric: starting bcd...z, A...Z, 0....8 (thus base 60), increments of 0.01 degree. Starting lat -90 and lon -180.

there is an "a" between the lat and lon.

Your above URL works for me and immediately displays the marker.

Please note that after the page loads the url changes.

In general, load the page and all info / layers that you want, with correct zoom level, etc, and after click in the location you want to add the marker. Then copy the URL.

Careful checking of the URL shows which parts load different info.

If you want a very accurate location (eg: your house) you can also use the same method in the opposite way:

zoom all the way in, click on your house to show the marker, then zoom out, set layers, etc, and after copy the url.

Hope this helps :)