Traditional wood archery bows do have a unique moisture requirement as compared to fiberglass bows. The care of a traditional wood bow is part of the craft and art of learning archery. Moisture content (MC) is what makes wood flexible or brittle (generally). Preferably the wood should be between 6-12% (MC) and 7-10% to be ideal. If a bow goes above 12% it can be more rubbery, not shoot as fast, or get 'set' a permanent bend in the wood (which is pretty natural anyways). If the bow is too dry, it becomes brittle and can break or shatter while stringing or shooting. A Humidity/Temperature Gauge can be very helpful, as well as, a humidifier.
Different woods absorb water at different rates. Also wax and oil can delay water absorption as well. Generally, traditional wood archery bows should be placed in a controlled environment two weeks before shooting especially during extremely dry months. The chart below shows basically where a wood's moisture content would be at a certain temperature and humidity. So, if a room was kept at 80oF at a 50% percent humidity, in two weeks the archery bow's moisture content would be about 9.1%- good. But, if the temperature is 94oF at a 20% humidity then the bow's moisture content would be 4.3%- potentially bad. Always be safe.
Once your traditional wood bow reaches a proper moisture content level, it is always a good idea to wax it (and the string, as well). This will help moisture loss during the heat of the day.