The Weather block is a PHP block. You need to add the phpblock function code to your lib-custom.php file:
function phpblock_getweather () {
global $_CONF;
$path = $_CONF['path_html'] . "weather";
include_once($path . "/display_weather.php"

;
$display = getweather();
return $display;
}
After you've added the code to lib-custom, create the PHP block from the block admin.
The PHP block should call the function phpblock_getweather.
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