Updated May 16th 2025
If you’ve been googling because you have older family members telling you that your breastfed baby should have extra water on those really hot days, you’re in the right place. As an International Board Certified Lactation Consultant, breastfeeding is my specialty. And I can tell you, if your baby is under 6 months old, they don’t need any extra water no matter the temperature. They just need you!
Breastmilk is almost 90% water (87.5% if you want the specifics) and meets all of their hydration needs. If your baby is formula fed, even partially, they too do not need any extra water under 6 months old. The water required to mix formula will be enough for your baby.
The reason this extra water could be harmful is it may lead to water intoxication. Young babies do not need the additional water as it can shift their mineral (electrolyte) balance. This is the same reason formula has very specific preparation instructions when it comes to how much water to use.
The other issue with giving babies under 6 months old water on hot days is it displaces breastmilk. Breastmilk is filled with energy from carbohydrates, fats and proteins as well as vitamins and minerals (and so much more) and it’s essential for a baby’s growth.
So what do you do instead? Here’s 3 tips for breastfeeding your baby in the summer heat.
1. Feed on Demand (nurse or bottle)
When the weather is hot, you’re thirsty. This is just normal for all human so yes, your baby will be thirsty if they’re out with you on a hot day. What do you do when you’re thirsty? You drink more often. So your baby is the same. Offer them a drink (nursing or bottle) more often in the warmer weather.
They may also just have a bunch of really short feeds (same way you take several sips of water). This is normal. If your baby is bottle fed they may also do the same, smaller amounts more often. Additional water on a hot day is never recommended for a baby under 6 months old.
If your baby is older than 6 months, you can offer 2-4 oz of water in a 24 hour period usually alongside their solid foods. You don’t need to go much beyond this as breastmilk will still be the primary source of their water intake. I love using an open cup like the EZPZ silicone feeding cup to practice their drinking skills around 6 months when they start solids.
2. Keep Yourself Hydrated (with minerals)
First things first, drinking more water is not a way to increase your milk supply. When drinks like bodyarmour, coconut water and gatorade work for *some* people, it’s because of the minerals in there. Minerals (like potassium, sodium and magnesium for example) are needed to bring the water you’re drinking into your cells to actually hydrate your body.
So being hydrated while breastfeeding means you’re focusing on your minerals as well as water. This is a mineral drink recipe that I use with my clients. It’s super easy to make, delicious, hydrating and breastfeeding safe!
The coconut water provides an excellent source of potassium as well as magnesium.
Orange Breeze – 1 serving
- 4oz (120 ml) coconut water
- 4 oz (120ml) orange juice
- 4-8oz (120-250ml) water
- pinch of sea salt (about 1/8 tsp)
Directions:
- Mix everything in a large glass or shaker cup, add ice and enjoy! I also love to swap the plain water for sparkling water for a nice “mocktail’ effect
3. Stay Cool (shade and breastfeeding clothes)
Keeping both of you cool is also important. Try spending as much time in the shade as you can when you’re out and bring a little battery powered fan if you have one. Covering your baby’s car seat or stroller with a blanket has been shown to actually increase the temperature inside (the greenhouse effect) so it’s best to leave it uncovered, dress your baby appropriately for the warmer weather and find some shade.
When you’re nursing in the summer, especially out in public, it’s hard to have multiple layers on without getting too hot yourself. I’m always quite warm in the summer so am not a fan of multiple layers but sometimes that makes nursing feel a little more challenging. Everyone has a different comfort level with nursing in public. What I find personally helpful is the two-shirt method where you wear a tank top under your shirt. This way, if you lift your shirt to nurse, your stomach/midsection isn’t exposed
I wear The Naked Nursing Tank because it’s made exactly for this and it’s super comfortable. They are made from cotton and bamboo so they are breathable too. This nursing tank is designed to cover your midsection and accommodates any bra type or size and with sizes from XS to 5XL they are size inclusive. You can check them out here and if it’s something you’d like to add to your collection of nursing clothes, you can save 10% off your purchase with affiliate code MOTHERHOODBLOOMS at checkout.
I hope you’re feeling all set to enjoy a summer with your baby!
References:
Williams H. G. (2006). ‘And not a drop to drink’–why water is harmful for newborns. Breastfeeding review : professional publication of the Nursing Mothers’ Association of Australia, 14(2), 5–9.
World Health Organization. (2024 October 2). Breastfeeding Questions and Answers. who.int online: https://www.who.int/news-room/questions-and-answers/item/breastfeeding