Background: The influence of seasonality on food security and nutritional status is widely accepted. However, research has typically focused on rural households and has not explored the specific mechanisms underlying seasonal effects.

Objective: To investigate the role of seasonality in determining the food security and nutritional status of low-income urban households and to isolate specific pathways through which seasonality has its impact.

Methods: Secondary panel data from CARE/IFPRI were utilized. Three rounds of data were collected from approximately 600 households in low-income areas of Dinajpur, Bangladesh, from 2002 through 2003, twice during the monsoon season and once in the dry season. Household-level surveys collected data on income and expenditure, employment, urban agriculture, health, and assets. Height and weight measurements were taken from children between the ages of 6 and 72 months. Paired t-tests and logistic fixed-effects modeling were then used to explore the role of seasonality.

Results: The prevalence rates of food insecurity, wasting, and inadequate growth were all significantly higher during the monsoon season as compared with the dry season. Dietary diversity and lost work due to the weather were identified as specific pathways through which season affected household food security. However, mechanisms hypothesized to contribute to seasonal declines in nutritional status, such as child illness, were not found to be significant.

Conclusions: Season had a significant effect on both food security and nutritional status in Dinajpur, with households consistently worse off during the monsoon season. Initiatives to promote food market development, support employment during the hunger season, and prevent seasonal declines in nutritional status should be implemented.