Abstract:This study examined the temporal and spatial variation of the ionospheric critical frequency (foF2) over Hermanus (34.4°S, 19.2°E) and Grahamstown (33.3°S, 26.5°E) in South Africa during the solar flares of October 28, 2021. These solar flares were chosen because they included both M and X classes, which are the strongest and most intense classes that can affect ionospheric variability. The analysis utilized the southward magnetic orientation turning (Bz) and low latitude magnetic indices (Dst indices) obtained from Omniweb to differentiate foF2 variations of geomagnetic origin from those caused by solar flares. The ionospheric response to a solar flare was measured using the percentage deviation (%D) in the amplitude of the critical frequency from the reference.