THIS WEEKEND: The Latest Sunset of the Year

Last Sunday, June 20, summer OFFICIALLY started.

This was the "longest day of the year" as our Sun was above the horizon for the greatest amount of time, with over 15 hours of daylight. So, you’d think that this also means the earliest sunrise and latest sunset would also happen on this day, but they don't.

The earliest sunrise always happens before the summer solstice. The earliest sunrise this year (in Waterloo) occurred on Sunday, June 13^th at 5:31:22. On the first day of summer, June 20^th, the sunrise was at 5:32:09 – 47 seconds later than the week prior.

In Cedar Rapids, the earliest sunrise of the year was June 13th at 5:30:30, 48 seconds earlier than the sunrise on June 20^th.

But as the sun begins to rise later in the morning BEFORE summer begins, the sun sets later in the sky AFTER the first day of summer.

On Saturday night, June 26, the sun won’t dip below the horizon in Cedar Rapids until 8:46:23. It will set in Waterloo at 8:50:53. On Sunday night the sun will set one second earlier in both cities.

By the first day of Autumn (September 22), the sun will set nearly 1 hour and 45 minutes earlier, shortly after 7:00.

After the first day of summer, the amount of daylight begins to shrink. Between June 20^th and June 30^th, we’ll lose around three minutes of daylight.

By the first day of winter – the short day of the year – we will have lost over six hours of daylight.

But WHY are the later sun sets after the first day of summer?

According to Earthsky:

The latest sunsets comes after the summer solstice because the day is more than 24 hours long at this time of the year.

For several weeks, around the June solstice, the day (as measured by successive returns of the midday sun) is nearly 1/4 minute longer than 24 hours.