Adult-use cannabis markets are operating in multiple US states and abroad. Sales and licensing data for alcohol and tobacco are often used to understand consumption patterns and evaluate policy changes. Cannabis market data may provide similar insights, although these newly legal markets are complex and evolving, and the state data structures can differ. This study describes variations in market indicators and discusses the utility of cannabis market metrics from a public health perspective. We collected data from 5 early-adopting adult-use cannabis states: Alaska, Colorado, Massachusetts, Oregon, and Washington. Analyses focused on licensed retail outlets and retail sales revenues (pretax). Monthly data were collected from the opening of each state's adult-use market through June 2022. Joinpoint software was used to assess state trends and identify points of inflection in trends. Average sales per retailer for June 2019 and June 2022 were compared. Also described are retailers and revenue per population for 2022. All states showed 4 distinct periods of growth in retail licensee numbers. The greatest increases typically occurred in the first 3 to 4 months. Growth rates slowed to <1% per month for Colorado, Oregon, and Washington at months 25, 24, and 34, respectively. The number of cannabis retailers per 100,000 residents in June 2022 ranged widely, from 16.8 in Oregon to 3.0 in Massachusetts. Colorado, Oregon, and Washington each showed 4 distinct trend periods in adult-use retail sales: early rapid growth lasting <1 year, subsequent varied growth periods, and then declining sales in the most recent months, following early coronavirus disease 2019 period increases. Sales in Alaska and Massachusetts displayed more stable, consistent growth patterns. Sales per state resident for July 2021 to June 2022 also ranged widely, from $382.97 in Alaska to $180.94 in Washington. We found some consistencies and some variations in both point-in-time measures and trends in states' adult-use cannabis markets. Differences may relate to varied state policies and general contexts (eg, economies). Market data can be useful for public health monitoring, including understanding the effects of policies intended to protect health and safety. States providing publicly accessible cannabis market data create opportunities for such use. Our results underscore the importance of considering individual state regulatory frameworks and implementation timelines in studies of cannabis legalization.