REUTERS/Mark Blinch
This is just one more sign of a sea change in popular opinion about weed. Just recently, a Lancet study of US adults from 2002 to 2014 found an increase in usage from 10.4% to 13.3% and an increase in people perceiving no risk in occasionally smoking from 6% to 16%. And of course, legalization is gradually spreading across the country.
The chart below shows searches for the topic of cannabis, which Google gathers using deep learning.
In case you're wondering, state interest is highest in Colorado:
Metro interest is highest in Eureka, California: