This article describes how to develop a real-time weather prediction app in Flutter using the Tomorrow.io Weather API. The app consists of a single screen that displays the current weather and a 4-day daily forecast for a specific location. We’re creating this prediction app on Flutter because it is an open-source UI development kit, which means it can be integrated beautifully into desktop and mobile apps across various platforms, making it scalable.  If you wish to follow along with this tutorial, you must have the following set up: A free Tomorrow.io account to access their weather-related features and data Any IDE that has the Flutter SDK installed (i.e., Android Studio, VSCode) A basic understanding of Dart and Flutter This tutorial was verified with Flutter v2.5.1 and Android Studio v3.5.  So, with everything out the way, let's get started. Tomorrow.io is a SaaS weather intelligence platform that provides real-time weather forecasts. It offers one of the most reliable free-to-use weather APIs. They provide an all-in-one endpoint that makes it easy to retrieve weather data by making a single call to the endpoint. After creating an account with Tomorrow.io, we need to retrieve our apikey from the Development menu on the sidebar.  The image below shows the Development screen.  Step 1: Creating a new Flutter project Create a new Flutter project by running the following command in your terminal. flutter create weather_app Step 2: Installing Dependencies  Next, we need to add the dio package as a dependency in our project. The dio package will be used for making network requests.  Run the following command to get the newest version of the dio package in your project. flutter pub add dio This command automatically adds the dio package in your pubspec.yaml file. Step 3 : Creating the Weather Model Let's create a weather model class. The class should have instance variables, a constructor for initializing fields upon object creation, and methods for translating JSON data from the API to Dart Classes. It is recommended that we write a model class to make our code easier to read, understand, and maintain. Create a new dart file weather_model.dart and paste the following code in it.   The weather model is based on the structure of the JSON data we are to receive from the endpoint. Step 4: Setting up the ApiClient After creating the weather model class, we'll need to construct our ApiClient class, which will handle network calls to the API endpoint. The code snippet below shows how we get the weather data of a specific location using the Dio package. First, we initialize the Dio package with our baseUrl. Then, we specify our query parameters apikey, location, fields, units, timesteps, startTime, and endTime.   You can access the Tomorrow.io documentation to see a preview of the query parameters accepted by the Tomorrow API, and what data you can get from the fields attribute. Next, we create a method called getWeather, inside which we call the GET method on the Dio object and pass in the required parameters. Then, we await the response. If successful, we parse the JSON data and return it; otherwise, we produce an error message. That concludes the ApiClient class. Next, we'll build the UI for our weather application and consume the API data. Step 5: Consuming the API Data We have a single screen that displays the current and 4-day forecast weather statistics.  The code snippet below shows how we used the FutureBuilder weather widget to display the result of our getWeather method. If it contains data, it returns the weather data; else, it renders an error on the screen. If none of the aforementioned apply, we display the CircularProgressIndicator widget to indicate that our data is loading. In this tutorial, we've learned what Tomorrow.io is and how we can interact with its API to build a weather prediction application. The source code of the demo application is available on GitHub. We’ve done this using Flutter to enable integration into desktop and mobile applications, making it scalable for any use – private or public.