ozone.plot <- ggplot(airquality, aes(x=Day, y=Ozone)) + geom_point() + geom_smooth()
ozone.plot <- ozone.plot + facet_wrap(~Month, nrow=2)

solar.plot <- ggplot(airquality, aes(x=Day, y=Solar.R)) + geom_point() +geom_smooth()
solar.plot <- solar.plot + facet_wrap(~Month, nrow=2)

wind.plot <- ggplot(airquality, aes(x=Day, y=Wind)) + geom_point() +geom_smooth()
wind.plot <- wind.plot + facet_wrap(~Month, nrow=2)

temp.plot <- ggplot(airquality, aes(x=Day, y=Temp)) + geom_point() +geom_smooth()
temp.plot <- temp.plot + facet_wrap(~Month, nrow=2)