These data include sample information and gene sequence reads for amplicon sequence variants from a study of freezing and storage duration effects on diatom-environment relationships. This dataset is associated with the following publication: Smucker, N., E. Pilgrim, C. Nietch, and C. Carpenter. Freezing periphyton samples and storage duration do not affect the use of diatom DNA metabarcoding to determine effects of stressors on streams. ENVIRONMENTAL MONITORING AND ASSESSMENT. Springer, New York, NY, USA, 197: 1360, (2025).