Plotting cumulative day-of-year precipitation can helpful in assessing how the current year’s rainfall compares with long term averages. This plot shows the cumulative rainfall by day-of-year for Philadelphia International Airports rain gauge.
The source data was downloaded from the Pa Climatologist website for the period 1949:2016. The period 1970 – 2016 was used for the analysis because the data archive does not include January data for 1950 – 1969.
The blue line represents the average day-of-year cumulative rainfall while the minimum and maximum years are shown in grey. The current year, 2016, is shown in red. As of July 24, there was a 5.18 inch negative anomaly in rainfall at the station.
This chart was created in R using base graphics commands.