Final answer:
Austin, Texas can hold more water vapor than Boise, Idaho due to its higher temperature, as warmer air has a greater capacity to hold water vapor.
Step-by-step explanation:
Among Boise, Idaho at 25°C and Austin, Texas at 35°C, Austin will be able to hold more water vapor. The capacity of air to hold water vapor increases with temperature because warmer air has more energy, allowing more water molecules to be in the gaseous state.
Because Austin is hotter than Boise, the air in Austin can contain more water vapor before it reaches saturation, which is the point at which air cannot hold any more water vapor and condensation begins, leading to precipitation.