From Desert Operations Wiki
The weather in the beginning does not play any role. It will be first important when you first Attack or Spy out sent on a player. It will play a role on the time it will take for the delivery of goods from the Trade. The time it will take for the Espionage Units to arrive at the destination will be directly related to the weather. For the battles it will still depend on the Units. You can build the weather station in the Command Center. It is required so that you can see when the next weather change will take place. The weather will change every 22 minutes.The weather will change every 22 minutes.
These are the different types of weather in the game: