STATS: June and the shortest day – Cape Town

We’re into June (cue comments of “where does the time go?” etc.) and Cape Town (last time I checked) is located deep (about 33 degrees deep) in the Southern Hemisphere.
The relevance of those temporal and geographical observations is that June contains our shortest day. And this year, much the same as every other year, June 21st has won through once again. [polite applause]

Note: I’m writing this on the morning of June 1st, but as I don’t know when you’ll read it, some of the tenses might be a bit off. What a tense situation (lol, geddit?) that may would have will been!

Today, June 1st, in Cape Town the sun rose at 0743, will reach its meridian at 1244, and set at 1745, giving a daylength of 10 hours, 02 minutes and 08 seconds.
Today is 52 seconds shorter than yesterday. I know you’ll notice/have noticed.

On June 21st, in Cape Town, the sun will rise at 0751, reach its meridian at 1248 (33 degrees (who knew?) above the horizon), and set at 1744, giving a daylength of 9 hours, 53 minutes and 32 seconds.
That’s more than a second shorter than June 20th was and a whole 2 seconds shorter than June 22nd will be.

BUT…

The days only get longer because the sun sets later. The sunrise continues to be at 0751 until June 24th and then gets even later (0752) until 5th July. However, this delay is offset by the later sunset to the extent that by July 8th, we’re back to a daylength of over 10 hours.

On June 21st, the sun will be 152.034 million kilometres from Cape Town, and while than might seem quite a long way away, we’re going to drift even further away until (again, obviously) the 5th July when we will be 152.092 million kilometres away. That might not sound like a big difference, but that’s an extra 580,000 km, meaning that the sunlight will take an extra 1.935 seconds to reach us on July 5th as it does/did/will have did on June 21st. I know you’ll notice/have noticed/have will did taked note.

For comparison, Cape Town’s longest day is December 21st.
On December 21st, in Cape Town, the sun will rise at 0531 (2 hours and 20 minutes earlier than June 21st), reach its meridian at 1244 (80 degrees above the horizon), and set at 1957 (2 hours and 23 minutes later than June 21st), giving a daylength of 14 hours, 25 minutes and 05 seconds (4 hours, 32 minutes and 27 seconds longer than June 21st.)

As for Cape Town’s latest sunset this year: you missed it (or maybe you didn’t, but it’s gone already) it was 2001 on January 6th. The sun that day was “just” 147.101 million kilometres away. Light from the sun took 16.648 fewer seconds to reach us on January 6th than it will on July 5th. And light goes fast, hey?

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