Dealing with humidity in Delhi
insänt av Arun Palaniappan i Delhi forum
I agree with Pramod in that you will have to shift to the hill stations to avoid the Indian summer. The weather you describe in Delhi isn't that humid (as compared to Mumbai or Chennai both coastal metros).
If your work is indoor an air-conditioner would relieve you of any discomfort. If you work outdoors try the local fan based coolers that spray water to cool the surroundings. They work quite well and are low priced.
The monsoon usually reaches Delhi by the first week of July. You should be relieved of the heat and humidity by then.