Working on outdoor farms affects elderly farmers’ health, especially those who have chronic diseases. This study aims to identify the risk factors related to perceived hot conditions on outdoor farms among elderly Thai farmers aged 60 years and older with chronic diseases. A cross-sectional study was conducted on 352 elderly farmers in nine sub-districts of Nong Suea District, Pathum Thani Province, Thailand via convenience sampling. Questionnaires were used as instruments to gather data about demographic and working factors. The risk factors associated with elderly Thai farmers’ perceptions of hot conditions on outdoor farms were identified by using binary logistic regression. The most common chronic illnesses were hypertension (35.8%), heart disease (34.4%), and diabetes mellitus (24.5%). More than 60.5% of the participants perceived their hot conditions to be high. The results of binary logistic regression show that low income and work duration ≤8.0 hours per day were risk factors related to perceived hot conditions on outdoor farms (P value < 0.05). These findings may be used by relevant authorities to support elderly farmers by emphasizing the importance of individual and work-related factors. Relevant government agencies should consider formulating working standards in hot conditions specifically for elderly farm workers.