So in general, regarding perishable foods like meat, most dairy, unshelled eggs and shell eggs (in the US) , cooked casseroles, and so on: if the food (or its perishable components) have been at room temperature for more than two hours, you should discard that food.
This directly effects how comfortable it will feel outside. Many times, relative humidity can be misleading. For example, a temperature of 30 and a dew point of 30 will give you a relative humidity of 100%, but a temperature of 80 and a dew point of 60 produces a relative humidity of 50%.
Humidity is the level of water in the air, the more water vapour in the air the higher the humidity. If the humidity level exceeds the amount of water air can hold condensation occurs forming dew if it's warm or frost if it's cold. When air is at a high altitude and has a high humidity then clouds start to form.