The best time to view the International Space Station from Earth depends on the viewer's location and where the space station is in its orbit. The best way to find ideal sighting times for a location is to sign up for NASA's free Spot the Station service.
At SpotTheStation.NASA.gov, visitors can sign up for free email or text message alerts that give several hours' notice from when the space station is scheduled to be visible from a location. This service only notifies subscribers when the space station is going to be high enough in the sky to see for a long period of time. Depending on the location, sighting opportunities can emerge anywhere from twice a week to once a month.