  The age of exascale computing has arrived and the risks associated with
neutron and other atmospheric radiation are becoming more critical as the
computing power increases, hence, the expected Mean Time Between Failures will
be reduced because of this radiation. In this work, a new and detailed
calculation of the neutron flux for energies above 50 MeV is presented. This
has been done by using state-of-the-art Monte Carlo astroparticle techniques
and including real atmospheric profiles at each one of the next 23 exascale
supercomputing facilities. Atmospheric impact in the flux and seasonal
variations were observed and characterised, and the barometric coefficient for
high-energy neutrons at each site was obtained. With these coefficients,
potential risks of errors associated with the increase in the flux of energetic
neutrons, such as the occurrence of single event upsets or transients, and the
corresponding failure-in-time rates, can be anticipated just by using the
atmospheric pressure before the assignation of resources to critical tasks at
each exascale facility. For more clarity, examples about how the rate of
failures is affected by the cosmic rays are included, so administrators will
better anticipate which more or less restrictive actions could take for
overcoming errors.
