Parsing JSON object in PHP using json_decode

I tried to request the weather from a web service supplying data in JSON format. My PHP request code, which did not succeed was:

$url="http://www.worldweatheronline.com/feed/weather.ashx?q=schruns,austria&format=json&num_of_days=5&key=8f2d1ea151085304102710";
$json = file_get_contents($url);
$data = json_decode($json, TRUE);
echo $data[0]->weather->weatherIconUrl[0]->value;    

This is some of the data that was returned. Some of the details have been truncated for brevity, but object integrity is retained:

{ "data": 
    { "current_condition": 
        [ { "cloudcover": "31",
            ... } ],  
      "request": 
        [ { "query": "Schruns, Austria",
            "type": "City" } ],
      "weather": 
        [ { "date": "2010-10-27",
            "precipMM": "0.0",
            "tempMaxC": "3",
            "tempMaxF": "38",
            "tempMinC": "-13",
            "tempMinF": "9",
            "weatherCode": "113",
            "weatherDesc": [ {"value": "Sunny" } ],
            "weatherIconUrl": [ {"value": "http:\/\/www.worldweatheronline.com\/images\/wsymbols01_png_64\/wsymbol_0001_sunny.png" } ],
            "winddir16Point": "N",
            "winddirDegree": "356",
            "winddirection": "N",
            "windspeedKmph": "5",
            "windspeedMiles": "3" }, 
          { "date": "2010-10-28",
            ... },

          ... ]
        }
    }
}