Activity patterns of ectothermic animals are affected by weather, time of day, and season, but quantifying these effects can be logistically challenging. We used an automated radio telemetry system to quantify Ornate Box Turtle (Terrapene ornata) activity patterns for two years in northern Illinois. Continuously collected activity data were paired with meteorological data collected from the site to determine factors influencing turtle behavior. Temperature, relative humidity, rain, year, month, time of day, and reproductive status affected activity levels. Increased activity levels corresponded with rain events, and males were generally more active than females, especially during spring and late summer. Overall, turtles were less active during an uncharacteristically warm and dry year compared to a year with conditions that were closer to the long-term average. Bimodal daily activity patterns have been reported in more southerly populations, and we found similar patterns near the species’ northern range limit, indicating that thermal constraints may limit activity of this species across its range. Activity comparisons between a year with normal meteorological conditions and an abnormally warm and dry year provide insight to the effect that further onset of climate change may have on the activity of Ornate Box Turtles.