Night Light of Salem (Illinois) from space (United States) Src. Average luminocity for 10x10km area is 25.7614% and for 50x50km: 4.5127%.
Square area 10x10 km:
 2.76%
 3.08%
 2.76%
 6.01%
 2.27%
 3.9%
 2.6%
 3.9%
 6.49%
 24.68%
 41.56%Square area 50x50 km:
 0.37%
 0.6%
 0.57%
 0.56%
 0.47%
 0.66%
 0.43%
 0.98%
 1.13%
 3.57%
 90.66%Clear (daylight) street map image can be seen on geolist.org.
Map coordinates:
39° 10' 27" North, 89° 38' 55.5" West
38° 37' 37.2" North, 88° 56' 44.2" West
38° 4' 32.1" North, 88° 14' 33" West
Some cities around Salem sort by population:
• Mount Vernon
		34.6 km =21.5 mi, 
173°
• Centralia
		19.9 km =12.4 mi, 
235°
• Effingham
		64.9 km =40.3 mi, 
32°
• Highland
		64.2 km =39.9 mi, 
281°
• Vandalia
		39.3 km =24.4 mi, 
340°
• Benton
		70.1 km =43.6 mi, 
178°
• Greenville
		50.1 km =31.1 mi, 
306°
• Fairfield
		58 km =36 mi, 
118°
Sources (retrieved 2019-11-25):
» Earth at Night: Flat Maps 2012, 2016