Increasing humidity and highs around 80 degrees are forecast in the Baltimore area Monday, with a chance of showers or thunderstorms in the afternoon, according to the National Weather Service. A warm front moved over the area overnight, with lows in the mid- to upper 60s. Some drizzle and fog was expected to be possible in the early morning hours. Temperatures were expected to rise into the 70s by mid-morning and near 80 degrees by midday. Relative humidity was forecast to be 50-60 percent during the day with dew points in the lower 60s, a level at which humidity starts to become perceptible for most people. A 40 percent chance of showers or thunderstorms is expected in the afternoon and evening. The next few days are expected to be hotter and more humid. Highs are forecast in the mid- to upper 80s Tuesday through Thursday, with dew points rising to the upper 60s. Lows are forecast in the upper 60s and lower 70s.