The trouble with camping and hiking is that you often never know what the temperature or weather is going to be. I always recommend to people to dress in layers and bring layers that are appropriate for the time of year and climate you will be camping or hiking in. There is a big difference between hiking in a dry climate versus a wet climate. Also if your hiking or camping around hills or mountains you should consider that different elevations can change how hot, cold, wet or dry the climate is.
Overall I suggest you plan and lay out everything you plan to pack and try use a layering system. Most importantly, you have remember that the day you don’t pack a rain jacket and pants is the day you will be wet cold and upset. So be sure to pack a rain layer. Finally, if you are hiking or camping in a sunny area you should consider clothing that is made to protect you from the sun and keep you cool and not just rely on sun block.