Night Light of Valongo (Porto) from space (Portugal) Src. Average luminocity for 10x10km area is 81.6672% and for 50x50km: 59.0814%.
Square area 10x10 km:
 32.79%
 32.79% 19.64%
 19.64% 6.82%
 6.82% 10.88%
 10.88% 10.88%
 10.88% 7.14%
 7.14% 10.06%
 10.06% 1.79%
 1.79% 0%
 0% 0%
 0% 0%
 0%Square area 50x50 km:
 14.96%
 14.96% 12.67%
 12.67% 7.17%
 7.17% 9.55%
 9.55% 10.77%
 10.77% 7.94%
 7.94% 6.16%
 6.16% 5.59%
 5.59% 6.5%
 6.5% 6.6%
 6.6% 12.09%
 12.09%Clear (daylight) street map image can be seen on geolist.org.
Map coordinates:
41° 42' 57" North, 9° 12' 6.1" West
41° 11' 19.8" North, 8° 29' 54.9" West
40° 39' 27.2" North, 7° 47' 43.6" West
Some cities around Valongo sort by population:
• Rio Tinto
		5.2 km =3.2 mi,  257°
257°
• Ermesinde
		5.5 km =3.4 mi,  303°
303°
• Fânzeres
		3.5 km =2.2 mi,  227°
227°
• São Pedro da Cova
		5.1 km =3.2 mi,  181°
181°
• Baguim do Monte
		3.6 km =2.2 mi,  275°
275°
• Campo
		2.8 km =1.7 mi,  98°
98°
• Sobrado
		4.4 km =2.7 mi,  56°
56°
• Gandra
		5.6 km =3.5 mi,  75°
75°
Sources (retrieved 2019-11-25):
» Earth at Night: Flat Maps 2012, 2016