1) Distance

You don't want to choose an alternate that's too close to your original destination, because your chances of finding better weather could be slim. On the other hand, choosing an alternate too far away may pose other issues, like increased fuel requirements. Look at the forecasts, and pick an airport that has weather to comfortably get you down if you have to divert.

2) Approaches

What kind of approaches does your alternate have? Do they align with the forecasts winds, or will you have to circle-to-land? Is there a precision approach? Filing an airport as an alternate that only has non-precision approaches, especially in low IMC conditions, will make your diversion more challenging.

3) Nonstandard Alternate Minimums

When you do file an alternate, verify that the airport doesn't have non-standard alternate minimums. If they do, you'll have to verify that the forecasted weather is going to allow you to legally file the airport as an alternate. Also, consider why the airport has non-standard alternate minimums. Is it close to terrain? Could the terrain adversely affect the weather? If so, you may want to pick a different alternate.

4) Weather Forecasts

Watch weather trends before you decide to file an airport as an alternate. If the weather at the original destination is moving in the direction of the alternate, you might want to plan for an alternate in a different location.

5) Fuel Requirements

You need enough fuel to go from your departure airport to your destination, to your alternate and there after for 45 mins at normal cruise. If you are planning to bring a lot of payload, you may not have enough fuel to get all the way to your alternate and fly an approach. Plan accordingly!

6) Services

Choose airports that can accommodate you if your flight doesn't go as planned. Consider factors such as hotels, fuel availability and hangar space.

What else should you consider for alternate airports? Tell us in the comments below.