Dietitians working at evacuation shelters conduct weighed food records (WFR) for multiple days for dietary assessment. Because the menus in evacuation shelters do not change much from day to day, this study examined whether 1- and 2-d WFR are sufficient for dietary assessment at shelters and identified dietary components that can influence the number of assessment days. Overall, twenty-six WFR were collected from ten shelters in Kumamoto Prefecture, and the amounts of energy; protein; vitamins B1, B2 and C and salt were calculated. Correlation analysis and paired sample tests were conducted to examine significant differences between ‘one- and two-consecutive- or non-consecutive-day WFR’ and ‘three-consecutive-day WFR’, which were set as the standard in this study. Additionally, the (CV for the categories by meal and dish were calculated to examine the variables that affected the large variations. As a result, 1-d WFR had significant positive correlations with the standard; thus, it could be used for the triage of shelters requiring nutrition assistance as a substitute for 3-d WFR. Two-consecutive-day and non-consecutive-day WFR showed a stronger correlation with the standard compared with the 1-d WFR. For energy and nutrients and dish categories, ready-to-eat foods had larger CV than boxed meals or foods from hot meal services. Whenever the meals included ready-to-eat foods, a two-non-consecutive-day WFR is recommended considering large between-day variations. Salty soup or beverages affected the variation of some nutrients. Our result would help municipalities to consider the number of WFR during emergency.