The rainfall only happens during a certain part of the year and that determines when to plant and when to harvest grain.
Grain needs water to be planted and to grow and because it rains in the winter it allows for the grain crop to grow and then to dry out for harvesting in the summer
There is rainfall in the winter months that allow grain to be planted and grow. In the summer months, the crops are harvested.
The beginning of the grain agriculture is in the winter during the rainy season. The grain fields are plowed and planted.
Early rain starts in October so November and December are time to sow barley first, then wheat. When the end of Winter around March, barley was harvested first, then about fifty days the harvest of wheat is completed. So Passover is in March and Shavuot is in May (Pentecost). Early rain, late rain; and early grain (barley), late grain (wheat) kind of rhythm together.
When the rains come then the grain agricultural cycle can begin. In ancient Israel, this was in the Winter season between October and April. There was lower humidity and pressure, and regular cycles of precipitation, low pressure.
Rain falls in the winter months and this is when grain crops are planted and tended.
The wet winter season in Israel runs from October to April, and 82% of Israel’s rain falls from December to February, with the northern part receives most of the rainfall. Therefore, the winter is when the ground is filled with water, which is also ideal for cultivating grains. Summer month is the harvest month as the Mediterranean Sea breeze will help them separate the grain kernel from the chaff.