Sunrise and sunset visibility

[audrey]

I should be more observant, but...

On Oct. 11, sunrise (Concord NH) is at 6:56 am; how long before that does it actually start getting light enough to see without a headlamp?

Sunset is at 6:09 pm; how long do I have after that before I have to pull out the headlamp?

(Long hike planned before the days get any shorter).

Thanks!

 

[sardog1]

FWIW, hunters in NH are generally allowed to shoot one half hour before sunrise and after sunset. I've always found that to be slightly excessive for safe, accurate shooting. But I've also found that navigating without a headlamp is generally feasible 40-45 minutes or so before sunrise and after sunset.

 

[Mike P.]

FWIW, hunters in NH are generally allowed to shoot one half hour before sunrise and after sunset. I've always found that to be slightly excessive for safe, accurate shooting. But I've also found that navigating without a headlamp is generally feasible 40-45 minutes or so before sunrise and after sunset.

Same 1/2 hour in CT for hunting too. Depends on the target, distance and terrain, it would be tough in the woods, not too bad in a cornfield after it's been cut. Same for headlamps, away from the sun in a dark forest earlier than in a west facing open field or woods, post fall when leaves are not an issue post sunset. (except when the leaves cover the trail which may not show up well after the sun down.)

 

[Tom Rankin]

It depends also on moon phase (+), cloudiness (-), and tree cover (-).

And who knows which day this year is the latest sunrise?

 

[sardog1]

And who knows which day this year is the latest sunrise?

Must.keep.biting.tongue.

 

[audrey]

And who knows which day this year is the latest sunrise?

The day that DST ends?
Thanks all. Carrying 2 headlamps...

 

[Willie]

Civil Twilight is the period before sunrise and after sunset until the time when the center of the disk of the sun is 6 degrees below the horizon. "Beginning-of-Morning Civil Twilight" (BMCT) is the time of civil twilight preceding sunrise, and "End-of-Evening Civil Twilight" (EECT) is the time of civil twilight following sunset. During the civil twilight period, you can carry on all normal daytime activities without being hindered by any loss of natural illumination.

For Concord, NH on October 11, 2012:

BMCT: 06:27
Sunrise: 06:56
Sunset: 18:09
EECT: 18:38

Source for times

 

[Stan]

As Tom says, it depends. The cloud type and ceiling make a significant difference and I've sensed it getting dark well before sunset when there are storm clouds up above. I find that I can go quite long after sunset if I don't turn on my headlamp as my eyes gradually adjust to the dark. Once I turn it on, though, there's no turning it off as night vision takes several minutes to recover.

Navigators at sea use red filters on lights to read charts without ruining their night vision of the sea and landmarks. The only time I've used red filters on land was to observe loggerhead turtles making their way from their nests on the beach to the ocean. They navigate by the stars and perhaps by a sense of the earth's magnetism but an unfiltered light can upset their navigation system, most often to their demise.

... loggergeads are fascinating but endangered so I wouldn't even think of carrying one in lieu of spare batteries ...