Facebook used to be just a social network application where users could go to view new posts from their friends whether it be pictures or status updates, but it's transformed into a hub of busy information including posts from friends, sponsored ads from businesses, and news updates both from local and global sources. Facebook also now allows people to chat with friends through Messenger as well as make calls, although this is now separated out into its own standalone application, and it appears that there may be a new feature in testing as users are reporting seeing weather alerts pop up in their facebook feeds inside of the mobile app.
Not all users are seeing these weather alerts show up in their feeds, but for those that are they're appearing at the very top as a card-based alert just above the status update card. The alerts are displaying the current weather and they're accompanied by a polite message as well as an icon that matches the weather type. Although this is all that's really needed to know the weather at the time a user might open Facebook, should they desire more information like the actual temperature and temperatures throughout the rest of the day, users can tap on these weather alert cards and they will expand to reveal the additional details.
The expanded cards with hourly temperatures throughout the day look very similar to the cards you'll find in Google Now if you tap on the weather card to view the different weather conditions hour by hour. If the user wants even more details beyond the hour by hour temperatures, they can hit an included link which takes them to weather.com with more information. With Facebook looking to re-engage users and enrich the service experience, adding weather information makes quite a bit of sense as it might persuade people to open up Facebook more often, it also isn't the only new thing they have been working on as they recently made another push at live video which is set to hit the Android and iOS apps and include a redesign of some sort for the app. They have also started adding the ability for visually impaired users to more easily enjoy photos within the app through automatic alternative text that describes the picture.