Alternate Airport weather minima

This regulation sets the weather standard for listing an alternate airport in your dispatch or flight release. You can only designate an airport as an alternate if weather reports, forecasts, or a combination of both indicate conditions will meet or exceed the alternate weather minimums specified in your airline's operations specifications when your flight is expected to arrive there.

The key point is timing: you're looking at *forecast* conditions for your estimated time of arrival at the alternate, not current weather. Your airline's ops specs will specify what those minimums are for each airport (typically lower than standard approach minimums since you're only planning to use the alternate if needed).

This ensures that if you can't land at your destination, your planned alternate will actually be usable when you get there. Note that ETOPS alternates have different rules under § 121.624.

*This is a plain-English summary for study only. The official 14 CFR text on this page is controlling — always read the current regulation and consult a CFI.*