custom WU-forecast.php problem : Sorry.. this country forecast can not be proc

Suddenly today my weather page with custom script : $Version = "WU-forecast.php Version 1.10 - 22-Dec-2008
Shows the following message.

[color=red]Warning: Division by zero in /[root]/public_html/weather/forecast.php on line 422
Sorry… this country forecast can not be processed by this script.

Locations in the United States and territories should use the carterlake NOAA script.

Locations in Canada should use the Environment Canada forecast script.[/color]
I have not changed anything to my website anyone knows why this could be happening?

see the work done here