Impatiens is a thirsty plant. Its soil should consistently moist. Hanging plants may need watering every day, depending on the type of basket and the soil. Water impatiens deeply, allowing the water to drain out the basket's bottom. Empty the water from any collection saucers beneath the plant, as you want accumulated salts to wash from the soil.
Monitor impatiens closely in the days just after you hanging tells you how much water it needs. Watch for wilting of flowers and foliage, and touch the soil to determine its moisture level. If it feels dry, water it. If you feel that it's drying too quickly, relocate the basket to a location where it gets less sun.
Impatiens cannot tolerate more than a morning of sunlight without its flowers being damaged. Protect it from the afternoon sun, which is warmer than morning sun. A basket getting more sun dries out more quickly and requires frequent watering.
The type basket to pot a hanging impatiens contributes to the amount of water it needs. Plastic pots hold water better and keep soil moister than terra cotta pots. Another option is a wire basket lined with moistened, long-fibered sphagnum moss. Sphagnum moss tends to hold moisture very well,)