WeatherBox .NET allows ASP.NET web developers and designers to quickly add
weather forecasts to their web-site. Written entirely in .NET, WeatherBox
is a templated control with rich design-time support making customizations
and configuration easy. The data displayed by the control is entirely
managed through the various templates. Forecasts can be provided for a
fixed location or allow each user to select their own location, true
personalization for your visitors.

More: http://keyoti.com/products/weatherbox/dotNetweb/