Agricultural climatology relies on records of basic meteorological measurements having been taken over extensive areas and significantly long periods of time. These records form the basis for understanding climate variability and change and also for extracting statistically significant relationships between meteorological variables and soil and plant processes, plant, animal, and pest development, and seasonal yield. In addition to standard atmospheric measurements, agriculturists need measurements of soil temperature and soil moisture. These measurements are less widely recorded although they (especially soil moisture) are being recognized for their role in climate memory and hence seasonal forecasting.