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High-Frequency METAR Data



The High-Frequency METAR (HF-METAR) dataset consists of experimental 5-minute observations from select FAA Automated Surface Observing System (ASOS) stations and Automated Weather Observing System (AWOS) stations. The hourly reports from these stations are also included in the standard METAR dataset. The stations report an "AWOS Format Weather Message" each minute to the distributed FAA AWOS Data Acquisition System (ADAS). The data from all the ADAS units are then conglomerated at the FAA William J. Hughes Technical Center near Atlantic City, NJ, where they are routed to MADIS.

MADIS started receiving about 440 stations via a feed, courtesy of the Massachusetts Institute of Technology Lincoln Laboratory February 18, 2009. This was an experimental feed that was shutdown on July 29, 2011.

The MADIS team is currently working with the FAA to reestablish a direct feed from the FAA's Weather Messaging Switching Center Replacement (WMSCR) systems located in Salt Lake City, Utah and Atlanta, Georgia directly to MADIS' ingest system. The data will be updated every minute from approximately 1200 FAA sites.

Geographic Coverage


Data Schedule

From February 18, 2009 - July 29, 2011 stations reported once every five minutes. Once MADIS receives data through the FAA WMSCR feed, stations will report every minute.

Data arrive on a continuous, asynchronous schedule, and the current and previous hour's data are processed every 5 minutes. Data from this feed are stored in hourly MADIS files with observations starting at the top of the hour and ending at 59 minutes into the hour (e.g., the 0000 file covers 0000 - 0059).

Data that arrive after 2 hours following the time of the observation are processed in a "data recovery" mode, where once a day batch processing is performed to reprocess data that are 35 days, 7 days, and 1 day old. These data are available with all communications methods supported by MADIS except for ldm.


Typical daily volume for all MADIS datasets can be seen here.


No restrictions. All observations are publicly accessible.

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Last updated 7 November 2014