Once crops such as rice, corn, sugarcane, soybean and cotton are planted, they need rain at regular intervals for growth.
The annual monsoon rains are vital, because over half of India's farmlands lack irrigation, and the farm sector accounts for 14 percent of the national economy.
The monsoon, furthermore, is the leading determinant of rural spending on consumer goods ranging from lipstick to cars as two-thirds of its 1.2 billion people live in villages.
"The last couple of days' rainfall will nourish the soybean crop, which has entered the flowering stage," S.K. Srivastava, head of the state-run Directorate of Soybean Research, told Reuters over the phone from Indore, a soybean hub in central India.
India, the world's fifth-biggest producer of soybeans, is a major exporter of soymeal, derived after extracting the oil, and a leading supplier of soymeal to South East Asian countries, where it is preferred as an animal feed.
Rains were below average last week, giving respite to cane and rice areas of northern regions, which had recently been affected by floods following heavy rain in the Himalayas.
Weather officials said rainfall was expected to improve in the major crop areas of northwest and central regions but was likely to ease in the northeast region, which suffered from floods along with neighbouring Bangladesh.
This year's monsoon started on a weak note and had a poor run until late July, when rains revived in northwest and central India.
The monsoon has been weak for the past couple of weeks, but that is unlikely to reduce harvest prospects for most of the sown crops as they have entered the germination stage, when less rain is required.
"The overall scene for most of the crops is good except millet and pulses, while production of rice is expected to be better than initial expectations," J.S. Sandhu, the country's farm commissioner, said.
"The delayed monsoon could reduce millet and pulses output by 2-2.5 million tonnes in the current crop year," he said.
Sandhu added that the main rice crop is unlikely to be hit heavily, even though floods in some growing areas took many lives and made thousands homeless.
India produced a record rice output of 106.54 million tonnes in 2013/14 following an early spread of last year's monsoon over the main growing belts. That amounted to 40 percent of India's total grain output for the year of 264.77 million tonnes.
India's crop year starts from June with the onset of the annual monsoon, which runs until September. Summer crops are harvested from October.
India's weather office forecast a poor monsoon season in 2014. But it has shied away from predicting that the four-month season would turn into a drought year, even though the weakest rainfall in five years was recorded in the first month.
India has joined with Britain to create a dedicated research programme to improve forecasting of the South Asian monsoon.
British Energy Secretary Edward Davey, who accompanied Deputy Prime Minister Nick Clegg earlier this week to India, announced the programme will start from next year.
The initiative will receive funding of around 8 million pounds from Britain's Natural Environment Research Council, India's Earth Sciences Ministry and the UK Met Office.