Electromagnetic waves propagating through the Earth’s ionosphere are subjected to changes in group and phase velocities, refraction, dispersion, and diffraction. For systems like GPS, which relies on the usage of L-band signals, rapid and random fluctuations in the phase and amplitude (known as scintillation) of the signals passing through the ionosphere play a major role, as they may cause losses of lock and result in degrading the accuracy and reliability of such systems. Therefore, understanding the physical nature and ability to predict the scintillation has been a challenge since a long time for engineers and scientists. In this work, a climatological model of rapid random fluctuations in phase and amplitude of GPS signals has been presented for high latitudes of the northern hemisphere. The 50Hz GPS raw data from Canadian High Arctic Ionospheric Network (CHAIN) for the 24th solar cycle (2008-2019) have been used to study the climatology of the rapid fluctuations in phase and amplitude of the GPS signals. The statistical analysis has been performed in terms of phase and amplitude scintillation indices (𝜎𝜑 and 𝑆4). The results are presented for different geo- and helio-physical conditions, including solar and geomagnetic activity, season, local time and geographical/geomagnetic location of ionospheric pierce points. For the first time, the distribution of the signal phase and amplitude fluctuations are presented for the whole period of the 24th solar cycle. An important quantitative statistical relation of the phase and amplitude fluctuations in GPS signals have been established for the high latitude region. A theoretical explanation is suggested for the observed differences in phase and amplitude fluctuations.