Umamaheshwara vratam is generally performed when Sun or Surya Bhagwan enters into Vrischik rasi. Uma maheswar Pooja is also observed in Kartik month (Kartika masam). Before performing the Vrata consult and take suggestion from a Brahmin.
Umamaheshwara vratam is a main ritual to perform on Bhadrapad Purnima, the Full Moon day in Bhadrapada month. Usually, Brahmin communities observe Umamaheshwar vrata on Bhadrapad Pournami. Other devotees observe Uma Maheshwar pooja on Kartik Purnima, the Full Moon day in Karthik month.