A series of type curves is presented for estimating vertical groundwater fluxes in relatively shallow aquifers by using seasonal changes in groundwater temperature-depth profiles. Vertical groundwater fluxes are estimated by fitting a dimensionless parameter to the type curves when the amplitude of annual variations of groundwater temperature at several depths and the thermal diffusivity of the aquifer are known or measured. Both upward and downward groundwater fluxes are estimated by fitting temperatures observed in Nagaoka plain, Japan to the type curves agree well with the fluxes calculated from hydraulic conductivity and hydraulic gradient data. Measurements of seasonal changes in groundwater temperature and hydraulic gradients were analyzed to estimate the thermal diffusivity of the aquifer in situ that is close to the value reported in the literature. ¿ American Geophysical Union 1993