When is dua most heard?

In the last part of the night and after the obligatory prayers.

Narrated by Abu Umamah

It was said: "O Messenger of Allah, which supplication is most heard?" He said: "In the last part of the night, and after the obligatory prayers."

Jami' at-Tirmidhi 3499

What this hadith teaches

Make your dua right after the obligatory prayer, and at the end of the night before Fajr.

Reference and grade

Grade
Hasan (al-Albani)
Narrator
Abu Umamah

The hadith in Arabic نص الحديث

جَوْفُ اللَّيْلِ الآخِرُ وَدُبُرَ الصَّلَوَاتِ الْمَكْتُوبَاتِ

Arabic text of Jami' at-Tirmidhi 3499, as given on sunnah.com.