Get sunrise, sunset and moon phases from the web

http://www.usno.navy.mil/USNO/astronomical-applications/data-services

(Or a Google search on “sunrise sunset times”)

Did you know there are three definitions of twilight? Want to see a screen-filling image of the exact moon phase of today (when our NW nights are cloud covered?) This web site, courtesy of the US Navy, has some slick calculators that help you plan your climbs.

Knowing what time the sun rises and sets, the start and end of twilight, and the phase of the moon can be very useful in determining when to leave basecamp, the amount of useable light in the morning and evening, and how much moonlight you’ll have available on a given day. Give this web page a look, and bookmark it. It’s been added to the Mazama Links page as well.

Here’s an example.  You’re planning a climb of Leuthold Couloir on Mt. Hood on April 10.  Walking up the Palmer snowfield can easily be done in the dark, but you want daylight to see where you are going and to dodge ice chunks on the more technical part of the route.  You want to know what time you need to leave town in order to get to the start of the technical climbing at first light.

From the web, you see that the start of civil twilight, the first usable light, is at 6:04 am.  Round it off to 6:00am.  Now work backwards.  It takes:
1.5 hours to get from Portland to Timberline Lodge
1/2 hour to get geared up
3 hours for a steady paced team to get to Illumination Saddle
total = 5 hours

Thus, to arrive at Illumination Saddle at first light on April 10, you need to leave Portland no later then 1:00 am (6:00am first light minus 5 hours travel and hiking time).