S U M M A R YRadon is a naturally occurring radioactive noble gas generated within mineral grains of uranium bearing rocks by alpha decay from radium. The Amram tunnel (A. Bloch Geophysical Observatory) is a particularly suitable location for the investigation of radon variability. Located in the arid environment of the Arava desert, near Elat, the 170 m tunnel that constitutes the observatory enables radon monitoring in a desert environment and under fairly stable environmental conditions. The analysis of the temporal variability of continuous measurements of radon and environmental parameters at the Amram tunnel over a period of several years shows a complex temporal pattern characterized by non-stationary and multiscale features. Radon concentrations exhibit multiyear variability in the form of a increasing trend of ∼1000 Bq m −3 yr −1 in the mean and much larger trends up to ∼2500 Bq m −3 yr −1 in the maximum radon levels. Radon concentrations also display strong seasonal patterns, with maxima in summer and minima in winter, ranging from 2.5 kBq m −3 in winter to 35 kBq m −3 in summer. Intraseasonal variability is characterized by very large radon anomalies, with sharp increases of more than 20 kBq m −3 relative to the base level, that occur in spring and summer and last for several days. Daily periodic variability with maxima around midnight appears also in spring and summer, being absent in the cold months. Radon variability at seasonal, intraseasonal and daily timescales is associated with the air temperature outside the tunnel, specifically the temperature gradient between the external environment and the more stable environment inside the tunnel where the measurements are performed.

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A novel technique utilizing simultaneous radon monitoring by gamma and alpha detectors to differentiate between the radon climatic driving forces and others has been improved and used for deep subsurface investigation. Detailed long‐term monitoring served as a proxy for studying radon movement within the shallow and deep subsurface, as well as for analyzing the effect of various parameters of the radon transport pattern. The main achievements of the investigation are (a) determination, for the first time, of the radon movement velocity within rock layers at depths of several tens of meters, namely, 25 m/h on average; (b) distinguishing between the diurnal periodical effect of the ambient temperature and the semidiurnal effect of the ambient pressure on the radon temporal spectrum; and (c) identification of a radon random preseismic anomaly preceding the Nuweiba, M 5.5 earthquake of 27 June 2015 that occurred within Dead Sea Fault Zone.