The dependence upon atmospheric pressure of the cosmic muon flux in Hanoi has been measured to be ± permil per mbar in agreement with expectation from a naive estimate. The dependence over ground temperature is observed to largely reflect the correlation existing between temperature and pressure. Once the effect of this correlation is removed a smaller, barely significant temperature dependence of ± permil per ˚C subsists. | Dependence of the cosmic muon flux on atmospheric pressure and temperature
