Is it permissible to fast the month of Rajab?

It is permissible to fast in any month of the year, but the narrations regarding the virtue of fasting in Rajab are weak. It is better to fast on the days for which there are reports from the Prophet, peace and blessings be upon him, such as the days of Sha'ban, Mondays and Thursdays, three days from every month, the Day of Ashura, the Day of Arafah, and the first ten days of Dhu al-Hijjah.