<p>The current study investigates the natural laminar-to-turbulent transition in the boundary layers of straight (STR) and swept (SWE) wings. The experiments are conducted in a subsonic low-speed wind tunnel using two wings configurations employing infrared thermography and pressure measurements. More specifically, image processing is used to analyze the flow pattern and infer the effects of Tollmien–Schlichting (T-S) and crossflow (CF) instabilities at low to moderate Re numbers (Re &lt; 10^<b>6</b>), which is one of the main contributions of this research. Additionally, using the pressure distribution data as a reference, point analyses are conducted to explore the physical mechanisms of transition. The results of this study provide insight into the boundary layer transition region in straight and swept wings, concerning the effects of low Re numbers and their viscous associated implications, such as laminar separation bubbles (LSB) and adverse pressure gradient, phenomena that are encountered in many aerospace applications such as small UAVs with fixed wings.</p>