  Muon rate models play a key role in converting measured data into information
on the density distributions of a target. Any given muography measurement,
either in transmission or in scattering mode, requires a proper modelization of
the muon flux according to the localization and to the atmospheric conditions.
Two approaches are commonly used: either through semi-empirical models
calibrated on existing data or via Monte-Carlo simulations. The former requires
extrapolations to the field experiment conditions while the latter offers the
advantage of tackling down in an unique way all relevant parameters such as
barometric conditions, geomagnetic field, atmosphere density etc. Although
significant progress were made in the last decades, precision muography
experiments require more and more accuracy on the models, especially for the
muons close to the horizon where large disparities still remain. In this paper
we present detailed results obtained with the CORSIKA simulation framework to
emphasize and quantify the impact of the environmental conditions on the
sensitivity of muography measurements.
