Where You Live
In hot, humid, or dry climates, your body will need more water. If you live in the mountains or at a high altitude, you will also need more water. The weather or season is an important factor to consider. Perspiration may require more water in warmer months than in cooler months. You may become thirstier faster if you spend more time outside in the sun, in hot weather, or in a heated room as opposed to being in cold environments.
Your Eating Habits
If you drink a lot of coffee and other caffeinated beverages, you may lose more water due to increased urination. If your diet is high in salty, spicy, or sugary foods, you will most likely need to drink more water. More water is also important if you do not eat a lot of hydrating foods that are high in water, like fresh or cooked fruits and vegetables.
How active are you? If you are active during the day, and walk or stand frequently, you will need more water than someone who sits at a desk all day. If you exercise or have a lifestyle that is physically taxing, you will need to drink more to compensate for water loss.
If you have an infection or a fever, or if you lose fluids through vomiting or diarrhea, you need to replenish the lost water. If you have a medical condition, such as diabetes, you need to drink more water. Some medications, such as diuretics, can cause you to lose water, and hence it is important to factor in your health, medications, and conditions.
Finally, the best way to determine your personal water requirements is to listen to your body and drink enough water to quench your thirst, to begin with. Some experts believe that you should drink water continuously throughout the day, even if you aren’t thirsty. If you are unsure or have concerns about your water intake, you should always consult a healthcare professional.