The present study numerically investigates the wake dynamics of two circular cylinders in tandem, having diameter D and separated by distance L, at low Reynolds numbers (Re = 60–200) and varying horizontal offsets (L/D) using the finite volume method, focusing on the extended and reattachment regimes. Results show that both wake length and vortex formation length decrease with increasing Re and L/D, while vortex spacing demonstrates non-monotonic behavior. Flow visualizations highlight fluctuations in velocity and pressure gradients, offering insights into wake characteristics. The wake length behind the downstream cylinder initially increases with the Reynolds number, peaking before diminishing as the Reynolds number further increases. With greater spacing, the wake length consistently reduces. The vortex formation length is notably larger at lower Reynolds numbers but rapidly decreases with rising Reynolds numbers due to flow regime transitions. Iso-Q lines aid in visualizing vortex intensity and behavior as they move downstream. The results offer an understanding of the unsteady wake dynamics of tandem cylinders, essential for the design and enhancement of engineering applications involving bluff body flows.