Final answer:
The factor that is NOT considered when determining a nation's water footprint is the daily per capita amount of precipitation.
Step-by-step explanation:
The factor that is NOT considered when determining a nation's water footprint is 3) The daily per capita amount of precipitation.
The water footprint of a country is determined by the volume of water needed for the production of goods and services consumed by its inhabitants. The other factors listed - 1) The daily per capita use of fresh water, 2) The amount of water used to produce exported crops, and 4) The average temperature of the country - all contribute to the calculation of a nation's water footprint. However, the daily per capita amount of precipitation is not directly factored in because it is subject to natural variations and does not reflect the actual water use of a country.