Humidity is measured relatively, to the amount of sunlight and warmth. Sativa plants need a humidity level in a range between 40-60%. This is often why it grows incredibly well on the American west coast in the Emerald Triangle. However, humidity can be controlled even better in indoor settings. Drier conditions are generally not good for cannabis plants, but for Sativa in particular, they can dry out leaves and slow the rate of photosynthesis.
To recap: Sativa (in general) needs slightly more warmth, as well as more and different levels of nutrients. Still, these cultivation variables are worth controlling for apply to all cannabis plants, and every strain (and grow environment!) is different.
Only by measuring with precision equipment and monitoring progress and conditions in real-time can give you the clearest picture of what’s working, what’s worked before, and what your pathway to ever-increasing yields and consistent quality will be.