I want to use a for loop to calculate a 95% confidence interval for the mean of humidity by month in R,

for(i in 1:12){
  aa<-atmos_1995%>% group_by(month)%>% summarize(average=mean(temp))

  bb<-atmos_1995%>% group_by(month)%>% summarize(sd=sd(temp))

  lower_vector <-aa - 1.96 *bb/ sqrt(length(atmos_1995)) 
  upper_vector <- aa + 1.96 * bb / sqrt(length(atmos_1995))
  confi <- c(lower_vector[i], upper_vector[i])
  print(confi)
}

how can I change the code to have intervals for the mean of each month?