He will probably be the first prime minister to address the nation on August 15 without a script. Sources say he will not carry any notes with him, just a set of bullet points.
"If it rains, the PM has asked that no umbrella should be put up and he will continue his speech in rain," sources said.
Mr Modi reportedly didn't want bulletproof glass either, but security agencies would not hear of it.
He is expected to reach the Red Fort at around 7.20 am. After a Guard of Honour by the armed forces, he will unfurl the national flag.
His speech, which is likely to last 45 minutes to one hour, is set to break new ground in more ways than one. (PM Modi to Announce Financial Inclusion Mission on Independence Day: Report)
For the first time, seating is being prepared for more than 10,000 people to attend. Millions more can see it from home as the event will be live streamed in India and abroad. (Also read: Tamil Nadu Governor, Leaders Extend Independence Day Greetings to People)
An ambitious plan of the Information and Broadcasting Ministry includes sending "40 crore SMSes" to highlight Mr Modi's speech. Films and vignettes on his life will also be shown by state broadcaster Doordarshan. (Read: PM Modi's Independence Day Speech Eyed for Big Reforms)
Mr Modi, 63, is used to making long speeches without prepared text and is seen by many as a speaker who can keep his audience engaged.
Sources close to him say a prepared speech or a teleprompter would take away his from his natural flair for connecting with the people.
The PM's idol is former prime minister Atal Behari Vajpayee, the BJP veteran known to be one of the country's best orators. BJP leaders believe Mr Vajpayee's Independence Day speeches missed his sparkling wit as he read from a text.
Mr Modi, who led his party to a stunning victory in the national election, reportedly wants his first Independence Day speech to set a benchmark. He is likely to outline his government's priorities in broad strokes but avoid specifics. (Also read: Students in Chennai School Have a 'Big Idea' to Celebrate The Tricolour)
Sources say he is likely to talk about governance and restructuring, but no big schemes will be mentioned.