All doctors will tell you that you should always drink 8 to 10 glasses of water each day. During the summer months, if you are outdoors, exercising, spending time in the sun, you should always increase your intake of water. Your body sweats a lot during this time of the year and you need to replenish the fluids in your body. Always when you exercise or spend a lot of time outdoors during the warmer months of the year you should increase your water intake by another 6 to 8 glasses of water per day. However, if you are mostly indoors during this time of year it is fine to stick with the 8 to 10 glasses of water per day. You shouldn't need more if you're not out in the sun.