Almost every piece of advice you have read about how much water to drink was written somewhere colder than here. Eight glasses a day is the famous one. It is a tidy number, it is easy to remember, and it was never meant to be a rule for someone walking across a car park in Dubai in July.
So the honest answer to “how much water should I drink?” starts with a caveat: it depends on you, on what you are doing, and on where you are doing it. But that does not mean there is nothing useful to say. There is quite a lot.
What the official guidance actually says
Two bodies are usually quoted. The European Food Safety Authority puts adequate total water intake at about 2 litres a day for women and 2.5 litres for men. The US National Academies, working from survey data on people who appeared to be well hydrated, arrived at higher figures: roughly 2.7 litres for women and 3.7 litres for men.
Two details matter more than the numbers themselves.
The first is that these are figures for total water, not glasses of water. They include tea, coffee, milk, soup and the water inside food. In adults, food typically supplies around a fifth of the total and drinks the rest. If you eat fruit and cooked meals, you are already some way in before you pour anything.
The second is the sentence that tends to get dropped when the numbers are repeated. Both sets of guidance are explicitly written for moderate temperatures and moderate activity. They are a baseline for a mild climate. They are not a ceiling, and they were never intended to describe a Gulf summer.
What the heat changes
You lose water constantly through sweat and through breathing, and both go up when it is hot. That is not news to anyone who has walked from a car to a building here in August. What surprises people is how much of the loss is invisible. In dry heat, sweat evaporates almost as fast as it appears, so you can lose a meaningful amount of fluid without ever feeling wet.
The UAE takes this seriously enough to legislate for it. The midday break rule, which has run every summer since 2005, bans work in direct sunlight between 12:30pm and 3:00pm from 15 June to 15 September, and requires employers to provide shade, drinking water and cooling. If you work outdoors — on a site, in landscaping, in delivery, in security — your requirement is simply not comparable to the figures above. It is higher, and it needs to be spread across the day rather than made up in the evening.
The air conditioning problem nobody mentions
Here is the part that catches out people who spend the whole day indoors and assume the heat is not their problem.
Air conditioning cools air by condensing moisture out of it. That is how it works: warm humid air passes over a cold coil, the water vapour condenses, and it drains away. What returns to the room is cool and dry. Spend ten hours in it and you lose water steadily through your skin and every breath you take, without sweating and without noticing.
It is why office workers here get dry eyes, a dry throat and tight skin in the middle of summer, and it is why “I was inside all day” is not the reassurance it sounds like. A day spent in a cold, dry office is not a day off from drinking.
How to tell, without counting glasses
Counting is a poor system because almost nobody keeps it up. Reading your own signals works better.
- Urine colour. Pale straw is the target. Darker and more concentrated suggests you are behind. It is not perfect — vitamins and some medicines change the colour — but as a rough daily check it is hard to beat.
- Thirst, with a caveat. Thirst is a real signal and worth acting on. But it lags. By the time you notice it, you have usually been short for a while, so treat it as a prompt rather than a schedule.
- How you feel late afternoon. A dull headache, flagging concentration or unexplained tiredness around 3pm is worth a glass of water before it is worth a coffee.
The practical version of all this is not a target. It is a habit: a glass when you wake, one with each meal, one when you arrive anywhere, and more on any day you are outside or moving.
Children and older people
Children have a larger surface area relative to their size and are less reliable at recognising and acting on thirst, particularly when they are absorbed in playing. In hot weather they need to be offered water rather than left to ask for it. A bottle that goes with them, and an adult who reminds them, does more than any number ever will.
Older adults are the group most often missed. The sensation of thirst genuinely weakens with age — in studies, older people deprived of water reported noticeably less thirst than younger people in the same state. Kidney function changes too, which makes urine colour a less dependable guide than it is at thirty. For anyone older in the household, the useful approach is a routine of set times rather than waiting for a signal that may not arrive.
If you take medication that affects fluid balance, or you have a heart or kidney condition, your doctor’s advice on fluid intake outranks anything in this article. Some people are told to drink less, not more, and for good reason.
Why people here drink less than they think
Ask around and the reasons are remarkably consistent, and none of them are about willpower.
The tap runs warm — often very warm in summer, because the pipes and the storage tank spend the day in the heat. We have written separately about why that happens. A warm glass of water is not appealing, so people wait, and then they forget.
Chlorine is the other one. It is added deliberately, and it is doing an important job protecting the water on its way to you, but a lot of people can taste and smell it, and a lot of people therefore drink less than they otherwise would.
Then there is the logistics problem: the household that relies on delivered bottles, runs out on a Thursday, and quietly drinks less until the next delivery arrives.
We should be straightforward here. We sell water filters, so we have an obvious interest in this argument. But it is still the truest thing in this article: the biggest single factor in how much water somebody drinks is whether getting a good glass of it is easy and pleasant. Not motivation, not education, not a target on a phone. Access. Every household we have worked with over more than ten years tells the same story — when good water is three steps away and tastes of nothing at all, consumption goes up on its own, and nobody had to try.
That is the whole reason we care about taste and convenience as much as we do. It is not a garnish on the product. It is the product.
The short version
Somewhere between two and three and a half litres of total fluid is a reasonable starting point for most adults, more if you are outdoors, active, pregnant, breastfeeding or unwell. Check the colour rather than the count. Do not assume a day indoors is a day without loss. And if the honest reason you are not drinking enough is that the water in your kitchen is warm, or tastes of chlorine, or has run out — fix that, because that is the fixable part.
If you would like to work out what would suit your home, our system finder asks a few questions and points you at a sensible answer. No pressure either way.