代码如下：

<SCRIPT>
function getcookie(name) {
var my_cookie = document.cookie;
var start = my_cookie.indexOf(name + "@weather.qq.com" + "=");
if (start == -1) return '';

start += name.length + 16; //1 stands of '='

var end = my_cookie.indexOf(";" ,start);
if (end == -1) end = my_cookie.length;
return my_cookie.substr(start, end - start);
}
       var v=getcookie('default_city');
       if (v == '') v=80;
       document.write("<IFRAME ID='ifm2' WIDTH='189' HEIGHT='190' ALIGN='CENTER' MARGINWIDTH='0' MARGINHEIGHT='0' HSPACE='0' VSPACE='0' FRAMEBORDER='0' SCROLLING='NO' SRC='http://weather.qq.com/inc/ss" + v + ".htm'></IFRAME>");
</SCRIPT>

将代码放到您的BLOG页面适当位置即可。