There is 3 level of raininess : Arid (+0 Nutrient), Moist (+1 Nutrient) and Rainy (+2 Nutrients).
Rainy areas are found on the west of mountains. A river square may increase raininess.
- Drill an aquifer, which taps an underground aquifer, creating a river and may increase raininess. This also adds one energy point to each square.
- Build a condenser increases the raininess of its square and all adjacent squares over 2 radiuses. It however greatly increases Eco-damage.