Precipitation in the form of liquid water droplets greater than 0.5 mm. If widely scattered, the drop size may be smaller. It is reported as R in an observation and on the METAR. The intensity of rain is based on rate of fall. Very light (R--) means that the scattered drops do not completely wet a surface. Light (R-) means it is greater than a trace and up to 0.10 inch an hour. Moderate (R) means the rate of fall is between 0.11 to 0.30 inch per hour. Heavy (R+) means over 0.30 inch per hour. |