weather_app_layout_03.dart

Future<Map> getData(double latitude, double longitude) async {
  String api = 'http://api.openweathermap.org/data/2.5/forecast';
  String appId = '<YOUR_OWN_API_KEY>';

  String url = '$api?lat=$latitude&lon=$longitude&APPID=$appId';

  http.Response response = await http.get(url);

  Map parsed = json.decode(response.body);

  return {
    'temperature': toCelsius(parsed['list'][0]['main']['temp']),
    'description': parsed['list'][0]['weather'][0]['description'],
  };
}

double toCelsius(temp) {
  return temp - 273.15;
}

@override
void initState() {
  super.initState();
  getPosition().then((position) {
    getPlacemark(position.latitude, position.longitude).then((data) {
      getData(position.latitude, position.longitude).then((weather) {
        setState(() {
          _locality = data.locality;
          _temperature = weather['temperature'];
          _description = weather['description'];
        });
      });
    });
  });
}