The summer solstice is known to us as the longest day of the year, and in the northern hemisphere its official calendar date is always June 20, 21, or 22. In the modern world, most people simply assume that the summer solstice also means the first day of summer.
But every year, these same people always notice – or complain – that “it’s only April, or May, and look how hot it is! It’s not even summer yet!”
Well – maybe it is summer, and we’ve just been misunderstanding that.
Our little planet is actually tilted in the solar system’s plane by some 23.4 degrees. As the earth makes its one-year journey around the sun, sometimes we’re tipped more towards the sun and sometimes we’re tipped more away from it. This changes how much heat and light we get from the sun throughout the year, and that’s why we have changing seasons.
In the twenty-first century, with our modern instruments, we can calculate the exact time of the summer solstice by noting the day when the Earth has its greatest tilt in the direction of the sun.
But far back in prehistory, no one knew about the planet being tilted. It was important to know about events like the summer solstice, though, because then you could figure out when to expect the coming seasons to change. You would have a better idea of when plants would begin to die and animals to migrate, and you would know how soon to be prepared for the barren winter to come.
To determine the summer solstice, all that was needed was several years of careful observation from just one spot to see exactly where, on the horizon, the sun rose each day. These spots would be marked with large stones, which were not likely to be moved or destroyed by animals or weather.
It quickly became clear that during the warm times, the sun rose a little more to the north each day. Eventually, the sun seemed to stop for a day or two or three – the sol sistere, or “sun standstill” – and rose in almost that same northernmost spot on those days.
These were the longest days of the year at that particular location. After that, the sun began to rise a little more to the south again each day and the cycle began again.
Many people would raise a permanent marker at the spot of their sol sistere – their summer solstice. There are still many, many single standing stones throughout the world that were carefully placed millennia ago and still mark the exact moment of the summer solstice in that place.
Yet these ancient people did not consider the solstice to be the first day of summer. For them, it was midsummer, for they knew very well that that there were about an equal number of warm days before and after the solstice.
Even today, many enjoy celebrating the Summer Solstice and might visit some of the ancient sites to see how well our ancestors did when it came to determining this day – and might begin referring to it as Midsummer!