Motivated by the visual appearance of spatially denoised video sequences, we study the visibility of dynamic (temporal) noise. We investigate the visibility of noise for different spatial frequency bands. We conduct a subjective test with 22 observers. Included are two types of test patterns in the test: static (spatial) noise patterns and dynamic (spatiotemporal) noise. Eight spatial frequency bands are used for each pattern type. We obtain two main results: First, the contrast sensitivity of spatially low-frequency noise is significantly higher with temporal variation. Second, the noise visibility also depends on the content of the image or video. As the noise is masked by the content of the image, it becomes less perceivable. As higher frame rate might be used in future, a second test was performed comparing 24fps and 48 fps. Results show that the noise visibility is very similar. The significant increase of visibility with the temporal variation of spatially low-frequency noise should be respected in the design of future video processing methods.