Some aspects of the relation between monthly temperatures and rainfall,and its use in evaluating earlier climates in the Middle East

The quantitative relation between mean monthly temperatures and rainfall has been investigated for a hundred years period at Jerusalem. It was found that a decrease of 1°C in the mean monthly temperature is associated with an average increase of 13 mm in monthly precipitation, on the seasonal scale. The findings are consonant with previous results pointing to an increase of about 100 mm in annual rainfall for a decrease of 1°C in the seasonal temperature. Such coefficients may, to a first approximation and with some qualifications, be used in estimating rainfall in earlier periods in the Middle East, and to evaluate hydrological effects and potential risks in future centuries.