If you are not a big fan of always checking everything out in dashboard (I know a lot of people don't really like dashboard) or you simply want more info than what the weather widget has to offer, you can install this nice add-on that will bring you weather information anywhere you want it. You can choose to have it on the dock, as a window or in the menu bar. The application called WeatherDock is really well developed and offers loads of options that will let you choose to hide the Dock icon, to automatically switch the location of the weather it displays according to a schedule (you are home or you are at work) and a lot more. What you will get is also a lot more advanced that what is available in dashboard. It is really like visiting a full featured weather website. I really like the menu bar icon because it doesn't take up a lot of real estate and you get a lot of info as soon as you click on it. You can get WeatherDock here from MacUpdate.