The best viewing conditions may well be tonight with low humidity and clear skies, although Saturday and Sunday should also provide decent views.
All three nights the ISS will first show up in the western skies before crossing more to the south. Here are the times to look up around the immediate D.C. metro region:
Friday: Rise 9:49 p.m., Closest approach 9:54, Set 9:59
Saturday: Rise: 10:28 p.m., Closest approach 10:32, Set 10:37
Sunday: Rise: 9:30 p.m., Closest approach 9:35, Set 9:40
(Use NASA’s applet to find out rise and set times for your specific location)