Understanding AWOS, ASOS, and ATIS: Automated Weather Systems in the US. Weather reporting plays a crucial role in the safety and efficiency of air travel. Automated systems such as AWOS, ASOS, and ATIS provide real-time updates that ensure pilots and airport authorities are always informed.


Automated weather reporting systems, including AWOS, ASOS, and ATIS, provide crucial updates for safe and efficient air travel in the US. AWOS and ASOS report real-time comprehensive weather data, ATIS offers broader hourly airport information.

ATIS provides hourly comprehensive airport information, including active runway details and surface conditions, and typically includes weather data from an automated weather system like AWOS or ASOS, ATIS is exclusive to towered airports. Pilots generally check both ATIS reports and AWOS/ASOS reports for the most up-to-date and accurate weather data.


AWOS – Automated Weather Observing System

AWOS is an instrumental part of airport infrastructure in the US. There are two main types:

  1. Federally Owned/Operated AWOS: These are managed by the federal government.

  2. Non-Federal AWOS: These are commercially manufactured systems that receive certification from the FAA.

The chief purpose of AWOS is to provide real-time weather data. It generates and transmits updates every minute, capturing the latest weather conditions at the airport. Depending on the specific system in use, AWOS can report on various meteorological factors, making the data almost instantaneous.

There are nine levels of AWOS reporting, with the most common at many airports being AWOS-III. Even though AWOS reports are primarily automated, human observations might occasionally be included, especially during reduced visibility. If an AWOS operates without monitoring, it tags the textual output with "AUTO".

ASOS – Automated Surface Observing System

ASOS systems are mostly operated and controlled by the NWS, DOD and, occasionally, the FAA. They have a level of reporting comparable to an AWOS-III up to IV Z and offer hourly reports on barometric pressure, wind speed and direction, DA, visibility, sky condition, ceiling height, precipitation, and in some cases thunderstorm and freezing rain detection.

ASOS systems are the National Weather Service’s primary climatology network for observing and reporting weather in the United States and may be found in locations other than airports if they serve to improve weather awareness in locations pertinent to the public.

ATIS – Automated Terminal Information Service

Unlike AWOS and ASOS, which predominantly focus on weather data, ATIS offers pilots a more comprehensive view of airport information. This system is exclusive to towered airports.

The unique aspect of ATIS is the inclusion of human oversight. A person from the airport tower monitors the system, ensuring that pilots receive critical information. ATIS reports are typically disseminated hourly at 55 minutes past each hour. However, if there's a significant change in weather conditions, updates can be more frequent.

In addition to basic weather data - typically generated from an AWOS, ASOS, or AWSS system, ATIS offers insights about:

  • The active runway
  • Runway surface conditions
  • Notices regarding airport construction or any other essential details.

When the airport tower isn't operational, the ATIS system typically defaults to providing ASOS or AWOS reports.

Working with Mesotech

➤ Mesotech is one of only two companies who are fully FAA Certified by the Non-Federal Program to produce and sell AWOS-III or better that can provide real-time weather data to pilots and integrate into ATIS reporting. The Airport Weather Advisor™ AWOS system has been in continued use and development for over 25 years and is present on all seven continents including Antarctica. Mesotech offers free training with the installation of an AWOS and understands the ins and outs of working with the Non-Federal Program.