Measuring rainfall provides BWSC with important data used in monitoring the efficiency of our sewer and drain systems during storm conditions. We use this information to evaluate the capacity of our infrastructure and plan proactive maintenance projects. This data can assist in monitoring stormwater runoff into Boston Harbor and the Charles, Neponset and Mystic Rivers. 

BWSC maintains solar powered rain gauges on top of buildings throughout the city. These gauges log measurements of precipitation and report data every five minutes. BWSC provides this information and uploads this rainfall data on a regular basis. BWSC reports rainfall data as far back as 1999, depending on the year of installation for the various gauges.  

Although the Commission maintains these devices and checks the accuracy of them periodically, they are subject to factors which may lead to inaccuracies. Snow, hail, severe weather, tampering, debris, or a component not functioning can affect the data.  This can result in the loss of data which can be reflected in the totals under reporting the actual rain fall amount.



  • Click the plus/minus buttons in the upper left corner to zoom in/out of the map, or ...
  • Enter an address in the search box to locate a rain gauge in your area
  • Rain gauges display on the map when zoomed in


Moving Around the Map

  • Hold down the left mouse button and drag to pan the map