I do it this way (get the weather for Vienna, Austria)...
<?
$GrabURL = "http://weather.oneclick.gr/Europe/Vienna.go";
$GrabStart = "Temperature between <B>";
$GrabEnd = "</B>°C.";
@$file = fopen($GrabURL, "r");
@$rf = fread($file, 30000);
@fclose($file);
$grab = eregi("$GrabStart(.*)$GrabEnd", $rf, $printing);
$temp = explode("</B> and <B>", $printing[1]);
echo $temp[1];echo "°";
?>
just go to this site, and find the link for your city 🙂