Embora eu nunca tenha usado pelo que vi:
smeData = "INSERT INTO `rob-tabl` (`time.val`,`time.microsec`,`temp.degrees`, `humid.calc`,`pressure.calc`) VALUES (%s,%s,%s,%s,%s)"
cursor.executemany(smeData, data_array)
sem o loop for.
smeData = "INSERT INTO `rob-tabl` (`time.val`,`time.microsec`,`temp.degrees`, `humid.calc`,`pressure.calc`) VALUES (%s,%s,%s,%s,%s)"
cursor.executemany(smeData, data_array)