Extensive measurements were made to assess propagation characteristics of sounds produced by blast sources similar to military weapon systems for various source heights and weather conditions. Pyrotechnic explosives were used as blast sources at heights between 0 and 300 m. Two charge sizes were used: one with a sound energy level L_Q of 162 dB(C) and a second with 139 dB(C). The test site was flat and mainly covered by grass. The microphones were at a height of 4 m, and at distances between 250 and 2000 m in 8 azimuths. The weather conditions were recorded with two SODAR/RASS systems that provided the wind and temperature profiles for altitudes up to 400 m. The recorded sound pressure waveforms were processed to produce the one-third octave band and C-weighted levels for all blasts at all measurement points. The blast sound propagation characteristics for C-weighted levels changed significantly between a ground-level blast and a blast set off at 60 m, the lowest height above ground that was used. For source heights between 60 and 300 m propagation conditions changed marginally, such that the calculated propagation parameters for this range were assumed to be constant. Acoustically, the large blast source resembles heavy weapons. The influence of up- and downwind propagation characteristics was markedly more pronounced for blast sources set off on ground than for elevated sources at 60 m or higher. During daytime (with turbulence and negative temperature gradients) the blast sound propagation characteristics are nearly the same for up- and downwind conditions, but differ with source height. During night time, there were no differences between the propagation characteristics of the ground level blast sources and above ground sources (except for the correction for ground absorption and a geometrical correction). These results were incorporated into an engineering model used to estimate military artillery noise.