Why is it critical to know the weather at the alternate airport before arrival?

Understanding the weather at the alternate airport before arrival is essential primarily for safety reasons. If the weather conditions at the intended destination are unsuitable for landing, pilots must ensure that the alternate airport can accommodate their arrival safely. This entails checking for factors such as visibility, wind direction and speed, as well as runway conditions. Adverse weather at the alternate could lead to challenges in landing or even necessitate further diversions, which can compromise the safety of the flight and passengers. Knowing the weather enables the flight crew to make informed decisions, ensuring a safe approach and landing, and maintaining overall flight safety standards.

While other factors, such as fuel needs and runway conditions, are important, they are secondary to the critical need for safety upon arrival.