"It can rain today."
अनुवाद:आज वर्षा हो सकती है।
Yes, you are right. This sentence 'It can rain today' is wrong in the sence of 'आज वर्षा हो सकती है।'. The correct translation of this Hindi sentence is 'It may rain today'. 'Can' is used where we describe about power, efficiency or anything's capacity but where we describe about possibility we use 'may'.