Ionospheric refraction introduces significant delay and fading in the electromagnetic signals. This makes the ionosphere the most harmful layer of the Earth’s atmosphere to the electromagnetic signals emitted by satellites, impacting the reliability of GNSS services. Depending on the ionization level of the ionosphere plasma and the signal frequency, these errors can vary from a few meters to signal unavailability. The main factors influencing ionosphere plasma’s ionization level are the intensity of solar radiation and the Earth’s magnetic field. The main parameter to evaluate the behavior of the ionosphere is the Total Electron Content (TEC), existing between the satellite and the terrestrial receiver antenna. By predicting the TEC value, it is possible to predict the effects of ionospheric refraction and develop techniques to increase reliability in services that depend on GNSS. This study spans the four seasons from 2018 to 2023, utilizing measurements of ionospheric delays collected by the UTC(INXE). Daily, seasonal, and annual variations in Vertical TEC (VTEC) values are analyzed. A comparative assessment is made between the VTEC values obtained by the GPS P3 method and the Ionospheric Map method for each season until winter 2023. The Analysis of Variance demonstrated the compatibility and comparability of the two methods. Additionally, this investigation explores changes in the ionosphere behavior at the UTC(INXE) location during the geomagnetic storms caused by the solar explosions on April 21, 2023. The findings provide valuable insights for the ionosphere dynamics and can contribute to developing techniques to improve GNSS services’ reliability.