The town has an area of 2.978 ha with 24.3% being residential. Signagi District is adjacent, on the town’s east and southwest sides. Signagi is situated in the eastern foothills of the Gombori Range, a watershed between the Iori and Alazani valleys.
Signagi has a mild Mediterranean-like climate. There are four seasons, with winters being moderately cold while summers can be hot. The highest average temperature is in July at 24.3°C while the lowest average temperature is in January at 0.2°C. Average annual precipitation ranges from 602.1 to 949.7 mm, with the heaviest occurring during the spring months and early summer.