Objective To explore the association between meteorological factors and suicide in cancer patients. Methods Based on the Shandong Multicenter Healthcare Big Data Platform, data on suicide deaths of cancer patients were collected from January 2010 to December 2021. Meteorological data were extracted for the corresponding time. Conditional logistic regression models were constructed using case-crossover design to explore the association between meteorological factors and suicide risk. Results A total of 80 patients with cancer suicide deaths were included, including 48 males, 32 females, and 43 patients aged 60 and above. Suicide risk in cancer patients increased with increasing monthly average temperatures, with an OR of 1.20 (95% CI: 1.12 - 1.28). The ORs for monthly average maximum and minimum temperatures were 1.20 (95% CI: 1.13 - 1.29) and 1.19 (95% CI: 1.12 - 1.27), respectively. Monthly average sunshine duration and monthly average precipitation were negatively associated with the risk of suicide in cancer patients. However, no associations were observed on daily and weekly scales. In all subgroups, the increase in monthly mean temperature, monthly mean minimum temperature, and monthly mean maximum temperature was associated with the increased suicide risk of cancer patients. The risk of suicide among males, females and cancer patients ≥ 60 years were affected by monthly mean sunshine duration, while cancer patients < 60 years were more susceptible to the influence of monthly mean precipitation. Conclusion The meteorological factors are highly related to the risk of suicide in cancer patients, and psychological interventions for cancer patients during weather changes should be strengthened to reduce their suicide risk.