public class MainActivity extends AppCompatActivity {
String VersioRemota;
String Temp;
TextView Tv1;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate ( savedInstanceState );
    setContentView ( R.layout.activity_main );

    new Thread(new Runnable(){
        @Override
        public void run(){
            URL url = null;

            try {
                url = new URL("http://www.inforatge.com/alzira/main/wdl/clientraw.txt");

                BufferedInputStream bis = new BufferedInputStream(url.openStream());
                byte[] buffer = new byte[730];
                int bytesRead = 0;
                bytesRead = bis.read(buffer);
                VersioRemota = new String(buffer, 0, bytesRead);
                String Datos[] = VersioRemota.split(" ");
                Temp = Datos[4];

                bis.close();

            } catch (MalformedURLException e) {
                Log.w("", "MALFORMED URL EXCEPTION");
            } catch (IOException e) {
                Log.w(e.getMessage(), e);
            }

        }

    }).start();
    Tv1=(TextView) findViewById ( R.id.TextView1 );
    Tv1.setText(Temp);

}


}

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">

<TextView
    android:id="@+id/TextView1"
    android:layout_width="180dp"
    android:layout_height="61dp"
    android:layout_marginStart="116dp"
    android:layout_marginLeft="116dp"
    android:layout_marginTop="80dp"
    android:text="temperatura"
    android:textSize="30sp"
    android:textStyle="bold"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    tools:textColor="@color/colorPrimaryDark" />

public class MainActivity extends AppCompatActivity {
String VersioRemota;
String Temp;
TextView Tv1;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Tv1 = (TextView) findViewById(R.id.txtPrueba);
    new Thread(new Runnable() {
        @Override
        public void run() {
            URL url = null;

            try {
                url = new URL("https://www.inforatge.com/alzira/main/wdl/clientraw.txt");

                BufferedInputStream bis = new BufferedInputStream(url.openStream());
                byte[] buffer = new byte[730];
                int bytesRead = 0;
                bytesRead = bis.read(buffer);
                VersioRemota = new String(buffer, 0, bytesRead);
                String Datos[] = VersioRemota.split(" ");
                Temp = Datos[4];
                runOnUiThread(new Runnable() {
                    public void run() {
                        Tv1.setText(Temp);
                    }
                });

                bis.close();

            } catch (MalformedURLException e) {
                Log.w("error**", "MALFORMED URL EXCEPTION");
            } catch (IOException e) {
                Log.w(e.getMessage(), e);
            }

        }

    }).start();
    //
    //Tv1.setText(Temp);
}
}