100 Year rainfall data

Hi Folks,

I'm working on calculating my swale size using this calculator https://www.permaculturereflections.com/swale-calculator/. I'm struggling to find 100 year rainfall data for MA. Does anyone have a resource they've used in the past, I keep ending up on sites with interactive maps and charts, but this is not giving me the information that I'm looking for. What resources have you all used to gather your 100 year weather events? This is what I've found so far but it doesn't even go back 100 years, http://water.weather.gov/precip/.


Thanks,

Cornell has a site for NY and New England, including 100-year (and 200-year, and 500-year) rainfall totals, including upper and lower confidence boundaries:
http://precip.eas.cornell.edu/

Is that what you're looking for?

Weather Underground has data from airports that goes back 60-80 years.