For a while now, I’ve thought it somewhat silly that the first day of Summer falls on the solstice. This is the day where the Earth’s north pole is pointed as close to the sun as it will get, the sun will be the highest in the sky, and the northern hemisphere will receive more solar energy than any other day in the year. By all rights, this should be midsummer’s day.
And in times past, it was! The Celtic holiday of Litha celebrates midsummer, and their are seven others (Lammas, Mabon, Samhain, Yule, Imbolc, Ostara, and Beltane) marking eight equidistant spaces around the calendar. The longest day of the year is midsummer, and the shortest is Yule, i.e. midwinter. This just makes sense to me, I don’t know about you.
Of course, I also feel (and here we’re getting into mere opinion and personal attestation) that the middle of summer weather is more deeply in July than in June. Likewise, the more wintery part of winter is about a month or so after December 22, previously noted as Yule/Midwinter (known in popular society now as the first day of winter). So, from personal experience, I’d place the mid-seasonal day about one month after the currently selected first-day-of-whatever. I’d place midsummer’s day around July 15, and mid-fall around Halloween (Samhain), midwinter near January 30, and midspring on May 1.1
These are, of course, personal picks. For ease of use, I’d advocate going back to the Celtic calendar for seasonal variations and stop calling June 21 the first day of summer. It was bloody hot out yesterday, so why wasn’t it summer yet?
1If it were a true weather geek, I’d graph this and pick some points using objective temperature data, but I’m not. I’ll leave it as an exercise for the reader