Procambarus clarkii (red swamp crayfish) is a species of great concern in the Laurentian Great Lakes area due to the recent discovery of established populations in inland and Great Lakes-connected waters. Faxonius rusticus (rusty crayfish) is also a non-native crayfish which has spread throughout the Great Lakes and inland waterways in the past 40 years. Populations of both P. clarkii and F. rusticus are established in the North Shore Channel (NSC) of the Chicago Area Waterway System (CAWS) which connects Lake Michigan to the Mississippi River Basin. Previous work indicates that populations of P. clarkii may be temperature limited, particularly in the presence of competitors. Our work combines field and laboratory studies to determine the impact of temperature and competition on P. clarkii in the NSC and across the Great Lakes area. First, we leveraged catch-per-unit-effort (CPUE) data from annual crayfish trapping of the entire North Shore Channel since 2018 and water temperature data collected from 2023-2025 using iButton temperature loggers to determine how temperature influences P. clarkii distribution and density in our system. Second, we conducted laboratory experiments to test both the thermal tolerance of P. clarkii and how temperature affects competitive interactions between F. rusticus and P. clarkii. Our field study results indicate that the highest densities (average CPUE = 0.36 crayfish/trap) of P. clarkii occur where water temperature is higher (mean temp warmest month= 23.7oC, mean temp coldest month= 2.9oC) and F. rusticus population is less dense (average CPUE = 0.16). Further, our laboratory experiments indicate that P. clarkii is less active in lower water temperatures (13oC) than those in ambient (20oC; p<0.01). Preliminary results also indicate that F. rusticus won more competitive interactions with P. clarkii in cooler temperatures (5oC) compared to ambient (20oC; n=225, X2=13.15, df = 1 p<0.001). Overall, our studies demonstrate that P. clarkii becomes less active in cooler water, which may impact survival and ability to compete with F. rusticus. These results are directly applicable to other systems across the Great Lakes where managers are working to control populations of invasive crayfishes.