When picturing the typical Disney tourist, it is easy to think of bright shirts, khaki shorts and a Fanny-pack. But is a fanny pack really necessary?
When considering what to bring to Disney, it is important to think about its location. If you are considering Disneyland in Anaheim, California, it is a good idea to pack sun screen and a container for water. Dehydration is an easy mistake to avoid in Southern California if you remember to take care of yourself. Sunburns are another common mistake for both parks. Remember to reapply Sunscreen after one to two hours depending on SPF level. Also, it is important to put on more sunscreen after being exposed to rain, pools, or other moisture as it is likely to have warn off (even with water resistant brands).
One major difference between the USA Disney parks is the rain in Orlando, Florida. It is a good idea to pack a poncho (a plastic shawl they often sell for a higher price inside the park), and back up sun screen as well. A water proof or water resistant container or bag can also be a big help.
Keep in mind that both parks will check your bags before entering the park, so it is a good idea to keep the contents neat and accessible. Some people choose to pack their belongings in a clear bag but this is not a requirement by any means.
Although these suggestions are for Summer in specific, it is a good idea to check the weather and temperatures before reaching your destination. This can help you pack accordingly. Also, in Anaheim, don't expect a cloudy day to mean cooler temperatures. The cloud coverage at Disneyland, California, will actually make the temperatures feel much warmer! This is a result of the warm temperatures being trapped underneath the cloud coverage. Anaheim is located between the ocean and the mountains regions, and has a reduced ability to disperse heat and humidity. The smog is a visible example of this.