Checking the weather for a short afternoon flight showed visibility of more than 10 sm and clear skies locally, with a barely moving front off to the west. The forecast showed nothing unusual, although clouds and limited visibility were expected to arrive with nightfall several hours after my anticipated landing time. The temperature/dew point spread was narrow, but around the Great Lakes, we often had high humidity content at lower altitudes as moisture blew in off the water. Seeing ground-level dewpoints only a few degrees away from temperatures wasnt concerning. Overall, the weather looked great for a local sightseeing flight in the late afternoon.