Conditions on the east coast of India are different from the west coast. But it’s immaterial anyway, because Columbus was using his knowledge the Atlantic, and probably had no knowledge of the seas around India.
Sailing eastwards in higher latitudes, of course. I doubt Columbus made use of jetstreams.
The word “India” was, during Columbus’ days, understood in a much wider and looser sense than it is today; it was used not only to refer to what is now the Republic of India, but it covered pretty much all of what we now consider East and South East Asia. So don’t let the common phrase that Columbus was searching for a “passage to India” fool you: He wanted to go to East Asia - actually, the destination that he was really after was the city of Hangzhou, near Shanghai, which Europeans had heard about from Marco Polo. He understood that East Asia was big - even those historians who assert that Columbus died in the belief of having been in Asia (which is disputed) don’t deny that he knew he had discovered new islands; to them, he simply believed that he had found islands off the coast of Asia. So even if he had knowledge of the monsoons south west of the Indian subcontinent (which I doubt), that would not necessarily mean that those monsoons would have mattered to him.
Strictly speaking, North America is an island off the coast of Asia. 
Just take the “off” part starting from the Bearing Strait.
That was also 1/1/2 millennium in the past. Those sea trade route had long since been abandoned.
I’m pretty sure that, strictly speaking, the categories “island” and “continent” are mutually exclusive. Since North America is, conventionally, regarded as a continent, it can’t be an island, independently of its distance from Asia.
May I ask : What makes you think that the phrase is fooling me ?
Cite please ?
Perhaps that you were wondering why Columbus didn’t plan his voyage according to the winds around the Indian subcontinent?
What @naita said: You write about the weather conditions around the country we now call India. That implies you were thinking that this is where Columbus wanted to go. It’s not; his intended destination was included in the word “India” at the time but is in what we now call China, because that was the region of the fabulous riches Marco Polo had told Europeans about.
Here, for instance. Or here. Or, for a 19th century source, here (in German).
Please see the cite provided mentioning monsoons in my initial post - reproduced above. Nowhere is India referred to in its present geographic limits but the original limits. Monsoon winds were mentioned.
And "With the world’s strongest monsoons, this region stretches from the South China Sea into the Indian Ocean and includes Asia and the northern end of Australia. From June until September, summer monsoon rains occur in South Asian countries such as Vietnam, Thailand, Cambodia, Bangladesh, Laos, India, and Pakistan. From December until February, the monsoon rains move south of the equator towards Australia while South Asia experiences dry monsoon conditions. "
Hence I am unable to understand why you think I was referring to the current day geography of India.
None of those cites work for me. The cites provided are links to searches (in german) of online books of the term “columbus quinsay”.
Do you have a good cite to backup your claim " He wanted to go to East Asia - actually, the destination that he was really after was the city of Hangzhou, near Shanghai, …" with emphasis on the “really after” part.
You’re kind of contradicting yourself. On the one hand you insist that you didn’t mean what we now call India, on the other hand you want to see cites for the statement that he wanted to go elsewhere but what we now call India.
Nope
Only to the extent that the part of the world Columbus wanted to go, was heavily influenced by Monsoon winds. Assuming the Monsoon winds was common knowledge, why did Columbus pick August (peak Monsoon time) to sail out ?
This part is your claim - not mine. Your claim, if I understand correctly, is that Columbus’s planned destination was unaffected by the monsoon and therefore monsoon winds are not relevant and August was just as good a time to sail as any.
That is my claim, yes. With the added element that even if the monsoons were of greater relevance for the destination Columbus had in mind, it wouldn’t have affected his planning because he wouldn’t have known about them - unlike the prevailing wind patterns in the Atlantic, which he did know about, and which he did consider in his planning (in particular by picking for the return leg a route far further north than that of the leg towards America).
Now that we’ve clarified my claim, it would be good to clarify yours, so we can see where the disagreement is and which points, exactly, need to be supported by cites.
We did not have any disagreements.
I wanted to see citations backing up your claim that Columbus really wanted to go to Hangzou (China) and not India. Everything I have read pointed to Columbus wanting to go to India and China.
Then perhaps you present your cites for your claim that Columbus had two destinations in mind, not one - the countries we now call China and India (for I suppose you’re using those terms in their modern meaning; my point).
1492
August 03
Columbus sets sail
From the Spanish port of Palos, Italian explorer Christopher Columbussets sail in command of three ships—the Santa Maria, the Pinta and the Nina —on a journey to find a western sea route to China, India, and the fabled gold and spice islands of Asia
Bolding mine to highlight the cite you asked.
Let’s look at primary sources, most importantly, the diary from the first voyage: http://www.ems.kcl.ac.uk/content/etext/e020.html
Says in the entry for 21 October 1492 that he was determined to go to Quinsay, the contemporary European name for Hangzhou.
Really? I thought his goal was the Spice Islands, i.e., the Moluccas, which is part of Indonesia.
Dude, any knowledge European sailors had about monsoon weather patterns was long since gone by 1492.
There were (by ancient standards) substantial sea trade between Mediterranean Europe and South Asia, but by 1492, the European people who had experience and knowledge of Indian Ocean weather patterns were statistically likely to be dead a thousand years.
So no, Columbus is very unlikely to have have given the monsoon any thought.
It was certainly part of the overall project that the confirmation of the existence of a westward route to Asia would open up the wider region, including the Spice Islands, to European traders. But the immediate destination of the first voyage was Quinsay, i.e. Hangzhou. That’s because Marco Polo had written favourably about the riches of that city. Columbus wanted to deliver a letter from Ferdinand and Isabella to “the Khan” (he’s using Marco Polo’s 13th century terminology again, not knowing that the Mongolian Yuan dynasty from Polo’s days had meanwhile been overthrown by the Han Chinese Ming dynasty) and take a reply letter from the Khan back to Spain. Following this establishment of first contact, more voyages into the wider region would have followed.
This is true, although not for long - just a few years later the Portuguese started trading with India via a sea route going all the way around Africa.