Modern operating systems offer weather information out-of-the-box. There's Windows 10's weather app, and the Notification Center on macOS. But Ubuntu doesn't come with anything like this.
No matter: you can install something yourself fairly quickly. We've found two applications that add the current temperature to Ubuntu's top panel: My Weather Indicator, which a lot of weather detail, and Simple Weather Indicator, which as you might imagine offers only the basics. Here's how to install and use both.
My Weather Indicator: Lots of Information and Features
The somewhat confusingly-named My Weather Indicator puts the current temperature in Ubuntu's top panel. Installing My Weather Indicator isn't hard, if you know how to install third party PPAs in Ubuntu. Open the Terminal, then run the following commands.
sudo add-apt-repository ppa:atareao/atareao
sudo apt-get update
sudo apt-get install my-weather-indicator
The first command adds the atareao PPA to your system; the second updates your package manager; the third installs the indicator. When everything is done, you can find the new indicator by opening the Dash and searching for "Weather."
When you first run the program, you'll want to set a location. Click the indicator, then hit the Preferences button near the bottom.
This will open the preferences window, where you can opt to automatically determine your current location or enter a location manually. Up to two locations are supported.
Once you've entered your location, the weather should appear in an icon on your panel. Click it, and you'll see all sorts of weather information.
If you want a forecast, you can also see that easily by clicking the "Forecast" button.
Weather information is pulled from OpenWeatherMap, Yahoo, Weather Underground, or World Weather Online (though you'll need an API key for the last two choices.) One disappointment, at least in our tests: the weather map functionality seems to be broken. Still, there's a lot to like here.
You can also enable a desktop widget if you want, complete with a clock and weather conditions. There are several to choose from, including a few inspired by Android phones circa 2010.
Oh, and if you're not on board with the whole metric thing, be sure to also head to the "Units" tab and configure everything there to your liking.
Simple Weather Indicator
If all you really want is the current temperature, Simple Weather Indicator might be a better choice. This shows the current temperature in the top panel, and offers just a few details when clicked.
Again, you'll will have to install a PPA to get this working. Open the Terminal, then run the following three commands in order:
sudo add-apt-repository ppa:kasra-mp/ubuntu-indicator-weather
sudo apt-get update
sudo apt-get install indicator-weather
The first adds the kasra PPA to your system; the second updates your package manager; the third installs Simple Weather Indicator.
There's a lot less to configure for this one. You can enable automatic location detection, or manually enter coordinates. You can choose between Celsius and Fahrenheit. You can decide if the temperature is rounded off or not. And you can choose whether this program should start when Ubuntu does.
We love how simple this is, but understand that some people might want a little more detail. Both options work well, so use the one that works for you.