noctourism.travel
Sunset

Devils Tower National Monument

Crook County, WY

Sunset this evening was at 7:08pm, to the west at 274°. The low light starts at 6:29pm, 38 minutes before, the last of the daylight goes at 7:37pm, and the sky is fully dark from 8:47pm. Cloud at sunset: 100%.

The next 14 evenings

EveningLow lightSunset DirectionLast lightFull darkCloud
Thu Sep 17 6:29pm 7:08pm W 274° 7:37pm 8:47pm 100%
Fri Sep 18 6:27pm 7:06pm W 274° 7:35pm 8:45pm 100%
Sat Sep 19 6:25pm 7:04pm W 273° 7:33pm 8:43pm 5%
Sun Sep 20 6:24pm 7:02pm W 272° 7:31pm 8:41pm 70%
Mon Sep 21 6:22pm 7:00pm W 272° 7:29pm 8:39pm 7%
Tue Sep 22 6:20pm 6:58pm W 271° 7:27pm 8:36pm 71%
Wed Sep 23 6:18pm 6:56pm W 271° 7:25pm 8:34pm 8%
Thu Sep 24 6:16pm 6:54pm W 270° 7:23pm 8:32pm 0%
Fri Sep 25 6:14pm 6:52pm W 270° 7:21pm 8:30pm 78%
Sat Sep 26 6:12pm 6:51pm W 269° 7:20pm 8:28pm 91%
Sun Sep 27 6:10pm 6:49pm W 269° 7:18pm 8:26pm 42%
Mon Sep 28 6:08pm 6:47pm W 268° 7:16pm 8:24pm 6%
Tue Sep 29 6:06pm 6:45pm W 267° 7:14pm 8:22pm 40%
Wed Sep 30 6:04pm 6:43pm W 267° 7:12pm 8:20pm 72%

Reading the times

The low light begins when the sun is within six degrees of the horizon, and from then until sunset the light comes in long and warm across whatever faces it. How long that lasts shifts through the year, so the minutes in the line above are tonight's, computed, and the low light column carries the start for each evening. Sunset is the moment the top edge of the sun passes a flat horizon, which is what every published time assumes. A ridge or a formation to the west brings the real moment earlier, by an amount that depends on the skyline from the exact spot, so the table is the latest it can be rather than the moment it will be.

The last of the daylight goes at civil dusk, with the sun six degrees under. Until then, in clear weather, there is light enough to see the ground and the horizon without a flashlight, and after it the brightest stars and planets show and the skyline goes to silhouette. Full dark is the sun eighteen degrees under, and it is the same instant the night page starts its dark window from, because the two share the arithmetic.

Cloud

A clear sky gives a clean sunset and a short afterglow. Broken cloud high in the west is what lights up after the sun has gone, because the sun still reaches it from below the horizon. A solid overcast is a gray evening, and the times above still say when it gets dark. The figure in the table is total cloud cover at the sunset hour, from the same forecast the night pages use, and it reaches about sixteen days; it does not say whether the cloud is the low sheet that hides a sunset or the high broken layer that makes one.

Which way

Sunset moves along the horizon through the year, due west around the equinoxes, well north of west in June and well south of west in December, and tonight's bearing is in the line above. First-hand notes from someone who guides here are on the Devils Tower National Monument page.