Depending on the individual plant different temperature and humidity levels are recommended. But in general, plants don't like it too hot, too cold, or too dry (with certain exceptions of course). Finding and keeping a balance is important to the survival of your plants. To make it easier on you, the gardener, select plants that thrive in similar conditions weather conditions.
Consistency in temperature is important to plants. Once you find the ideal temperature, try and maintain it daily. It is okay for the plants to be colder at night time; this is natural as the same happens outside in nature when the sun goes down. An average temperature range is 65-75 degrees Fahrenheit (18-23 degrees Celsius) during the day and a drop in temperature to 60-65 degrees Fahrenheit (15-18 degrees Celsius) is acceptable. As this is within the temperature range most houses are kept at this should not be hard to maintain.
You may be tempted to place a plant beside a sunny window to keep it nice and warm. Just remember that exposure to extreme temperature ranges is not good for a plant. It can get overheated during the day and then too cold at night. Give the plants natural sunlight but doing so on a windowsill is not recommended.
Inside a house is a lot dryer than outside. A lot of plants like at least some moisture in the air. Controlling the humidity in the house will help the plants and you if it tends to get dry inside. You can purchase a mister or humidifier for your house or another option is to get the plant's leaves wet. By taking a spray bottle, you can lightly spray the leaves or you can use a cloth or sponge. Take care of any special instructions your plant may have, some do not like to get their leaves wet.