ggplot2 wind time series with arrows/vectors

Question

From meteorological data (hourly values of temperature, wind and humidity) I managed to plot time series of wind speed and direction. Now I would like to add wind vectors on

Answer 1

Compute the direction of the wind using decimal degrees. Assuming that you want 0 degrees to be North (up), use the following:

ggplot(data = wind, aes(x=datetime, y=temp)) + 
  geom_text(aes(angle=-wind_dir_degrees+90), label="→")