What is the magnetic deviation at 116 n longitude and 48 w latitude?

Answer 1

You're not making it easy on us, that's for sure.

-- First we have to figure out where exactly you're talking about, because

the coordinates given in the question are so corrupted.

-- "Longitude" is the E/W number, and "latitude" is the N/S number.

-- "Latitude" can't be more than 90 degrees, so we're going to assume that

you actually mean " 48 N latitude / 116 W longitude ".

That point is in western Montana, about 2.3 miles east of the Idaho state line, 4.6 miles

southwest of Heron MT, and maybe 79 miles west-southwest of Kalispell. That's the

location for the following magnetic declination. If that's not the place you're trying

to describe, then this isn't the correct figure.

As of 2011 April 09, the magnetic declination at that spot is 15° 9' East, i.e. your compass

points 15° 9' east of true north, and that figure is decreasing by 10' per year.

You're welcome.