Weather update client in PHP

<?php
/*
* Weather update client
* Connects SUB socket to tcp://localhost:5556
* Collects weather updates and finds avg temp in zipcode
* @author Ian Barber <ian(dot)barber(at)gmail(dot)com>
*/

$context = new ZMQContext();

// Socket to talk to server
echo "Collecting updates from weather server…", PHP_EOL;
$subscriber = new ZMQSocket($context, ZMQ::SOCKET_SUB);
$subscriber->connect("tcp://localhost:5556");

// Subscribe to zipcode, default is NYC, 10001
$filter = $_SERVER['argc'] > 1 ? $_SERVER['argv'][1] : "10001";
$subscriber->setSockOpt(ZMQ::SOCKOPT_SUBSCRIBE, $filter);

// Process 100 updates
$total_temp = 0;
for ($update_nbr = 0; $update_nbr < 100; $update_nbr++) {
$string = $subscriber->recv();
sscanf ($string, "%d %d %d", $zipcode, $temperature, $relhumidity);
$total_temp += $temperature;
}
printf ("Average temperature for zipcode '%s' was %dF\n",
$filter, (int) ($total_temp / $update_nbr));