The Radio Acoustic Sounding System (RASS) messages data describe hourly observations from around 120 stations distributed globally. The observations, which are later transmitted in reports, give measurements of parameters such as wind speed, and temperature. The data are collected by observation stations worldwide and transmitted within the RASS message.

Data are extracted daily at around 00 UT from the Met Office's MetDB system for the previous day's coverage.

The dataset contains measurements of the following parameters:

- Station height (in m)

- Virtual temperature (in Kelvin)

- Wind w velocity component (in m/s)

- Signal to noise ratio

See linked documentation for general information about surface station readings can be obtained from the abridged version of "MIDAS Data Users Guide", provided by the Met Office. This document describes the meteorological surface data in the Met Office Database - MIDAS. This guide is rich in information and is aimed at those with little familiarity with observing methods or instrumentation. Details of the WMO Meteorological codes used at weather observing stations (daily and hourly weather) explain the codes used in this dataset further are also linked to on this record.