In general, when looking for the cheapest flight to Paris, try to choose a flight departing in May for the best deal.
In general, most flyers find the cheapest time to book a flight to Paris is about 58 days prior.
In general, booking your departure to Paris for a Wednesday represents the best deal on airfare. Try to avoid a Saturday departure to stay away from the highest prices.
On average you can find the best deals on plane tickets to Paris when looking for flights with midday departure times.