December, January, and February, the remaining half being
distributed throughout the seven months--September, October,
November, March, April, May, and June."

_"Sub-Pacific Type.--_The term 'Sub-Pacific' has been given to that
type of rainfall which obtains over eastern Washington, Nevada, and
Utah. The influences that control the precipitation of this region
are much similar to those that prevail west of the Sierra Nevada and
Cascade ranges. There is not, however, as in the eastern type, a
steady diminution in the precipitation with the approach of spring,
but rather a culmination in the precipitation."

_"Arizona Type.--_The Arizona Type, so called because it is more
fully developed in that territory than elsewhere, prevails over
Arizona, New Mexico, and a small portion of eastern Utah and Nevada.
This type differs from all others in the fact that about 35 per cent
of the rain falls in July and August. May and June are generally the
months of least rainfall."

_"The Northern Rocky Mountain and Eastern Foothills Type.--_This
type is closely allied to that of the plains to the eastward, and
the bulk of the rain falls in the foothills of the region in April
and May; in Montana, in May and June."

_"The Plains Type.--_This type embraces the greater part of the
Dakotas, Nebraska, Kansas; Oklahoma, the Panhandle of Texas, and all
the great corn and wheat states of the interior valleys. This region
is characterized by a scant winter precipitation over the northern
states and moderately heavy rains during the growing season. The.
bulk of the rains comes in May, June, and July."