Imam Sadeq (AS) narrated from Imam Ali (AS) who said: In the month of Ramadhan ask (Allah (SWT)) a lot for forgiveness. But with Dua (supplication) the calamities will be removed and asking for forgiveness (from God) will eradicate your sins [1].
[1] Alkafi, Vol. 4, page 88.
source : shafaqna