Losing water weight occurs in less than a day. Water weight sheds through a vigorous workout or intense sweating. However, water weight increases when water goes back into the body. Proper precautions and safety measures are necessary when trying to lose water weight.
According to Muscle For Life, "water retention can really mess with your head when you're dieting to lose weight." Retained water weight doesn't equal increased fat. It's plausible to shed fat yet increase actual weight due to water retention. If the goal is to show a lower number on a scale, then weight should be checked immediately after shedding water weight. If the goal is health and fat loss, water weight shouldn't be an issue.