1.5 Issuance Times

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1.5 Issuance Times

The schedule issuance times are 0000 UTC, 0600 UTC, 1200 UTC, and 1800 UTC. NWS WFOs issue scheduled TAFs four (4) times a day, every six (6) hours. The issuance times are in Universal Coordinated Time (UTC).

The forecast period covers 24 hours; however, at designated airports (generally airports who service international flights), the forecast period is for 30 hours.

WFOs may choose to routinely issue TAFs more frequently than every six hours as a method of keeping the TAF as up-to-date as possible.

Offices providing TAFs for the FAA's designated core airports issue TAFs every three (3) hours. The issuance times and valid periods are listed accordingly.

Scheduled Issuance	Valid Period	Valid Period (30 hour TAFs)	Issuance Window
0000 UTC	0000 to 0000 UTC (next day)	0000 to 0600 UTC (next day)	2320 to 2340 UTC
0300 UTC	0300 to 0000 UTC	0300 to 0600 UTC
0600 UTC	0600 to 0600 UTC	0600 to 1200 UTC	0520 to 0540 UTC
0900 UTC	0900 to 0600 UTC	0900 to 1200 UTC
1200 UTC	1200 to 1200 UTC	1200 to 1800 UTC	1120 to 1140 UTC
1500 UTC	1500 to 1200 UTC	1500 to 1800 UTC
1800 UTC	1800 to 1800 UTC	1800 to 0000 UTC	1720 to 1740 UTC
2100 UTC	2100 to 1800 UTC	2100 to 0000 UTC

Note: FAA-Core airports are airports that are significant to the national air transportation system based on air traffic operations and passenger boardings. They are determined by the FAA. There are approximately 30 core airports. Your Aviation Focal Point can tell you if your office issues TAFs for any of the core airports.