This research full paper describes engineering doctoral students' nonresponse patterns on a departmental climate survey. As the U.S. engineering workforce does not reflect the diversity of the U.S. population, the departmental climate can be one lever that higher education leaders can use to identify specific policies, practices, and procedures in doctoral programs to increase the retention and success of students from historically excluded groups. During the summer and fall of 2023, 355 engineering doctoral students from 28 institutions in the U.S. responded to a climate scale that we developed to assess multiple climate factors associated with organizational commitment or member retention. Items included a six-point Likert-type response option and “not sure.” While most students responded adequately to the climate scale items with the Likert scale, a significant number of students also responded to the “not sure” option. Based on the climate and survey research in the literature, we hypothesized that these item nonresponses may stem from (a) the contextual characteristics of climate constructs or items and/or (b) student characteristics. Descriptive and inferential statistical data analyses showed that “not sure” item nonresponse differed by climate constructs and items as well as student characteristics. Among the six climate factors, on average, authenticity climate had the highest item nonresponse rates, followed by performance climate and diversity climate. While the item nonresponse rates increased by student age, at the item level analysis, item nonresponse rates varied by residency, gender, and first-generation status. There were no significant differences in the item nonresponse rates on underrepresented minority (URM) status, student disability, and LGBTQIA+ status.