What if Isha time never comes in summer?

Why Isha "disappears"

Isha begins when the twilight after sunset fades. The majority of scholars say this is when the red glow disappears; Abu Hanifah held it is when the white glow goes too. Many timetables define this as the sun being about 15–18 degrees below the horizon.

North of roughly 48 degrees latitude (London, Amsterdam, Berlin, Copenhagen, Seattle), the sun doesn't sink that far for some weeks around June, so twilight lasts all night. Further north, as in parts of Scandinavia, it may barely set at all. Isha's "sign" never arrives, but the obligation of five prayers stays.

How scholars estimate the time

When the Prophet ﷺ described a future day "as long as a year", the Companions asked whether one day's prayers would be enough. He said no: "Estimate its measure" (Sahih Muslim 2937). Scholars use this to estimate prayer times when the signs are missing. Common methods are:

• Nearest latitude: use the Isha time of a place around 45–48 degrees, where the sign still appears.
• Nearest day: use the Isha time from the last date when it was still visible.
• Portion of the night: place Isha at one-seventh, or the middle, of the time between sunset and sunrise.
• Fixed interval: for example 90 minutes after Maghrib.

Bodies like the European Council for Fatwa and Research have published guidance on this, and most UK and European mosques follow one of these methods. None is "wrong"; they are reasonable estimates. See Can I trust prayer time apps?

Combining Maghrib and Isha

Some scholars and mosques also allow combining Maghrib and Isha in these weeks to avoid real hardship, such as Isha after midnight followed by Fajr a few hours later. Ibn Abbas reported that the Prophet ﷺ once combined prayers in Medina without fear or rain, so as not to burden his community (Sahih Muslim 705). Don't make it a permanent habit, but it is a known option. See Can I combine prayers because of my class schedule?