The page shows you the monthly and year precipitation thus far for every ASOS site in the USA that reports the 6XXXX 3/6 hourly preciptation group in their METAR reports. The clickable versions of the images are very high resolution (5120x3000) with values (top) and station ids (bottom) easily viewable when viewed in that native resolution. Values/ids are plotted from lowest precip first to highest precip last, such that higher precip values stand out in case of overlapping nearby stations. Only non-zero rainfall stations are plotted, and year values are plotted only for stations that reported METARS in all of the months for the year.
