How to Tell How Much Sunlight Is Left 

How much sunlight is left?
Blue skies and a clear horizon mean you can estimate how much sunlight is left at the end of the day with just your hand.

“Let every dawn be to you as the beginning of life, and every setting sun be to you as its close.” ~John Ruskin

Have you ever been out there, wondering how much daylight you had left? Easy, you can just check your watch or your phone, right?

 

Right, that’s what I usually do. But what if for some reason you’re somewhere out there and you don’t have your phone or your watch, or the battery’s dead? 

 

It could happen, but if you have a clear shot at the sky and the sun is out, you can estimate with relative accuracy just how much light is left. 

 

For instance, I was out at the shore recently surf fishing, and I was wondering how much light I had left so I could estimate how much time I’d have left to cast before I had to pack it in. 

 

Here’s what the sky looked like. 

How much sunlight is left?
The sun is pretty close to the horizon, so I don't have a lot of daylight left. I can tell almost exactly how much just by using a hand.

I did have my phone, as evidenced by the fact that I have pictures here, but let’s just say I didn’t, I could still tell how much light was left, and so can you. 

 

Here’s how you do it. 

 

Estimating Remaining Daylight with Your Fingers and the Sun 

First thing I need to tell you is not to try this unless the sun is low in the sky. Looking at the sun is tough, even when it’s going down and you have sunglasses on, and it’s not good for your eyes, either.

 

Anyway, all you need to do is stick your hand out at arm’s length, like so. 

How much sunlight is left?
Each finger amounts to about 15 minutes of sunlight. As you can tell from the picture, only one finger "fits" between the sun and horizon - indicating that the sun will set in about 15 minutes.

Then, see how many fingers’ widths remain between the sun and the horizon. 

 

Each finger is roughly 15 minutes of light. That is, it takes the sun about 15 minutes to traverse the radius created optically by one finger when your hand is outstretched.

 

You might be thinking: “Wait, this is influenced by the size of your hands and fingers, not to mention the length of your arm!” 

 

Sure, it is. But this isn’t supposed to be used for the calibration of atomic clocks. This is just for you to eyeball (no pun intended) how much sun you have left before it sets.  

Now, just for reference, my hands aren’t that big, so each finger’s width for me is actually a little bit less than 15 minutes. It was like 5:47 PM when I took this picture, and the sun set at 6:00 PM that night. 

How much sunlight is left?
I checked with a second finger just to confirm my estimate. Yes, of course the size of your hands matter and each finger is not the same size as the others - but this is just for estimation.

As you can see, however, based on the fact that the sun is just peeking above my one finger, I had just about 15 minutes of light left. 

 

Following, if my entire hand was between the sun and the horizon, I’d have about an hour of sun left. You can stack your hands one over the other to calculate how much time is left out to two hours, but with that much light left, the sun is too high in the sky and would be blindingly bright anyway (under most conditions).

 

Not as accurate as a quartz movement, but not too bad either. 

How much sunlight is left?
The sun went down fully 13 minutes after I estimated that there were 15 minutes left, so the method is fairly accurate.

It’s Your Turn 

The next time you’re out there, remember, if you can see the sun and you have a straight shot at the horizon (more or less) you can tell just about how much sunlight you have left. 

 

Get out there and give it a go. 

 

Be safe. 

 

~The Eclectic Outfitter

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Eclectic Outfitter