Weather will likely play an important role when you plan your trip to Forbesganj, but bear in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually April and May, with an average temperature of 29°C, while the coldest months are January and December, with an average of 20°C. The rainiest months in Forbesganj are July, August, June and September, with each month seeing an average of 467 mm of rainfall.