Why does it seem like every year, as soon as the weather begins to warm up, women start having babies all over the place? Along with blooming flowers and lengthening days, it always feels like warm weather brings on the babies. When I was in grade school, as soon as spring arrived it seemed like someone was bringing in a birthday treat every week. Now, as a woman in my twenties, I have three friends who have given birth in the past two months alone … and there’s still a lot of summer left.
About four million babies are born in the United States every year, and interestingly, a disproportionate number of them are born during warm weather. According to the Centers For Disease Control, more babies arrive in the summer than any other season, and July, August, and September are the most common months for infant births in this country, with August hosting the most births out of any month of the year and February consistently having the smallest number.
Why Warm Weather?
In the animal kingdom, spring is a time when many species come out of hibernation and begin to breed … and give birth. Animals time their fertility and gestation to coincide with the best weather, because young born during the warm season will have a better chance of surviving. They’ll have more food sources, they’ll have lots of fresh water, and they are less likely to die of exposure. Animal mothers prefer to give birth during spring and summer because those seasons make it easier to provide for a whole litter. It’s hard to imagine a nest of duck eggs surviving during a snowstorm, or a hutch of bunnies learning to find food in the cold. Animals know that warm weather ensures their young’s survival.
In temperate zones of the Northern hemisphere, the birthing season for most animals runs from about April to September, but in the Southern hemisphere, it’s the opposite. Animals down under have their babies in December and January, since those are the mildest months for them. In places like Africa or South America where conditions are often dry and barren, animals give birth to their young to coincide with the rainy season, when food and resources abound. Even animals that live in the harshest climates time their birthing season to coincide with the best weather. Baby penguins in Antarctica hatch just in time to catch a brief bit of sunshine.
