Triggered situational interest in introductory courses can encourage student engagement, motivation, and value for the geosciences. In-person labs have traditionally played a unique role in triggering situational interest compared to lectures, but the COVID transition online disrupted these dynamics. We examine students' self-reported situational interest from 6,463 responses to weekly surveys in online introductory geoscience lab courses at five U.S. institutions during fall 2020 and spring 2021. Approximately half of students reported that labs were equally (49.4%) or more interesting (4.3%) online, compared to a hypothetical in-person option. Analysis showed a statistically-significant interaction between student situational interest and the combined effect of 1) the course the students were enrolled in and 2) the topic of the lab session (F (20, 6395) = 4.038, p < 0.001). However, topic and course together explain only about 4% of the variance in the dataset, indicating that other factors have a large role in triggering interest. Students who indicated that labs were less interesting online (46.3%) most often cited not being able to physically interact with instructional materials (56.3%) and difficulty interacting with peers (30.6%). When asked what revisions would increase their situational interest, additional hands-on interaction (22.8%) and increased relevance to their life or future career (20.2%) were the answer choices students selected most frequently. These findings identify modifications and enhancements grounded in students' self-reported interest that can inform the design of online introductory geology labs.