Page:Weather Facts and Predictions.djvu/38

 More rain falls in summer than in winter, and most in the autumn.

More rain falls by night than by day. [Because the cold at night condenses and cools the air, and thus diminishes its capacity for holding moisture in suspension.]

The amount of moisture in the atmosphere is greatest near the equator, and diminishes towards the poles.

The zone of greatest moisture follows the sun across the equator to the North or to the South as the sun's declination changes.

The regions of greatest heat are also the regions of greatest rainfall. More rain falls in the Northern hemisphere than in the Southern.

As to the rainfall in Great Britain—

More rain falls on the Western than on the Eastern coasts, in the ratio of 2, 3, or 4 to 1.

Localities having a small annual fall have most rain in the summer, but at wet stations, winter is the season of most rain.

In all except mountainous districts, the amount of rain increases about 2½ per cent. for every increase of 100 feet in elevation above the sea level.

The wettest place in the British Isles is the Stye Head Pass, one mile S. of Seathwaite in Borrowdale, where the average annual fall is 165 inches.

The driest district in England is that around Lincoln, where the average annual fall is only 20 inches.

Comparing the E. with the W. of England the average falls over the whole area, neglecting extremes, are 25 inches in the former, and 40 inches in the latter.