Onions are widely produced and consumed in the United States but pose a food safety risk without a kill step during raw consumption, as seen in recent foodborne disease outbreaks. Curing is an industry practice to improve storability and inhibit spoilage by drying the outermost scales of onions. Prior studies have found curing to inhibit human pathogen growth, but the climate conditions and exposures during curing remain poorly characterized. This study analyzed key differences in various climate variables using the North American Regional Reanalysis across locations and photoperiod varieties. K-means clustering was used to identify distinct climate profiles, from which representative temperature and relative humidity conditions were computed. Field exposure durations of onions were found to increase from 0 to 21 days with increasing latitudes. Low- and high-moisture climate profiles were most prevalent for field and artificial curing respectively, most significantly separated by vapor pressure deficit, relative humidity and rainfall.