Methods to analyse the meteorological effects on wave propagation conditions for radio and radar are reviewed. This includes meteorological and wave propagation models, as well as techniques for measurement of environmental parameters needed as input to the models. Since the late 1980´s the possibilities to calculate atmospheric effects on propagation loss and detection range have improved considerably, provided the refractivity conditions are known. A main reason for this is the introduction of propagation models based on parabolic equations (PE). With PE-models, which also can be used for communication frequencies, it is possible to consider horizontal variations in refractivity and terrain height variations. This is important when the environmental conditions are inhomogeneous along the propagation path, e.g. operations in littoral waters. The possibility to calculate the refractivity has also been improved by better point instruments for temperature and humidity, rocket sondes and IR-thermometers for measurements of the sea surface temperature. However, the possibility to determine horizontal variations of the refractivity and variation in time still are limited. Some solutions can be seen, e.g. the use of mesoscale meteorological models and remote sensing techniques using measurements from existing radio frequency transmitters.