Despite the hot climate and high humidity in the Jazan Region of Saudi Arabia, which increases risk for dehydration, no previous studies have assessed awareness of dehydration and fluid intake practice among adults in this region. Therefore, the aim of this cross-sectional study was to determine awareness of the dehydration state and fluid intake practices among 440 adults in the Jazan Region of Saudi Arabia. Out of the total, 51⋅8 % were male and 48⋅2 % were females. Good knowledge of dehydration definition and prevention and recommended minimum water intake was observed in 98, 95 and 75 % of the participants, respectively. Fifty-nine percent of the participants met the minimum daily requirement of 3 l or more per day. The age (95 % CI 1⋅003, 1⋅017, P value = 0⋅006), diabetes (95 % CI 1⋅028, 1⋅459, P value = 0⋅023) and prior hospitalisation due to dehydration (95 % CI 1⋅010, 1⋅378, P value = 0⋅037) were associated with higher water intake. Additional glasses of coffee (95 % CI 1⋅02, 1⋅115, P value = 0⋅004) and juice (95 % CI 1⋅039, 1⋅098, P value < 0⋅001) were associated with more water intake. The participants exhibited good knowledge of dehydration definition, symptoms and consequences. Intake of fluids such as ‘juice and coffee’ enhances more water intake. Although two-thirds of the participants met the recommended daily water intake, still one-third of them did not meet this level. Innovative approaches to enhance healthy drinking are warranted and may include partnering with patients to take an active role in hydration monitoring and increasing communication with the different healthcare providers.