Research Progress Report 186
Project 1185 	April, 1965

Measuring the Southern Indiana Forage Farm Climate

L. A. Schaal, U. S. Weather Bureau and James A. Newman, Agronomy Department

	The important weather vagaries of the year were probably the dry period the first 3 weeks of August and a period of no significant rain from September 29 to November 15. Severity was lessened by seasonally low solar radiation and, therefore, less soil heating.

	The year’s daily weather is pictured in a graph on the back of this report. Of first interest is the rainfall. Much of the spring rainfall (March, April, May) came in the tremendous rains of early March. On each of 3 days, rain measured more than 3 inches. April rainfall was well scattered but May was dry until the 27th. Preceding this time, soil and air temperatures had climbed and air temperatures almost touched 90°, but the rains of late May were shocking to soil temperatures and they, subsequently, dropped from the 80's to the 50’s. Temperatures escalated in early June and rains were frequent.

	June was nearly ideal for lush growth of forage crops as soil and air temperatures reached 90° in the presence of good moisture supplies. Some insects and diseases probably thrived too. A good period for hay harvesting occurred in the last week of June and before the 4th of July. All temperatures worked upward in the last half of July into the summer peak of early August. The lack of rain began to tell as cold and warm fronts passed without bringing precipitation. In the first 3 weeks of August only a few hundreths were measured.

	The first half of September was as dry and almost as hot as the first two-thirds of August; air temperatures exceeded 90°, but soil temperatures did not reach the heights of August. Diminishing solar radiation and resulting soil temperatures trended downward until some recovery in October and early November. This was a very dry period, but it would have been more damaging in June or July when solar radiation is higher. As it was, the fall drought limited forage growth. When the rains came in mid-November, soil temperatures dropped and the trend of temperature was toward winter.

	Evaporation was above the station average in all months except for July, which was a little below average. Wind miles were very high in April and August but low in July.

	Daily and monthly values of rain, snow, wind, air temperature, and soil temperature at several depths and some soil moisture measurements are in Climatological Data--Indiana, published by the U.S.
Weather Bureau.

PURDUE UNIVERSITY • Agricultural Experiment Station • Lafayette, Indiana