When can you have Cheap flight To New York?

From London

According to travel search engine skyscanner.com, the cheapest months to travel from London to New York are March, November, December (except for the holiday week), January and February. The most expensive months are July and August.

March airfares shown on Google Flights, for example, are just under $600 for most of the month and rise modestly to about $650 for most of April and May. At the end of June, however, airfares start to climb closer to $900. By the peak season – July and August – you can expect to pay more than $1,000. Fall fares are similar to those in the spring, hovering in the $600 to $700 range. On some days, you might be able to find flights under $600.

From Paris

Skyscanner.com shows similar trends out of Paris. The cheapest months to travel are March, early April, October, November and during the winter months (except over the holidays). As from London, the most expensive times to fly are July and August.

A peek at fares on Google Flights show fares range between $450 and $550 for most days during March and April. By late April, prices start to rise ahead of the expensive summer months, with fares of about $650. By late June, travelers can expect to pay closer to $900, and fares remain there for the rest of summer. Prices drop off at by end of August, and fares for September, October and November settle back to the $550 to $650 range.

From Frankfurt

Frankfurt has similar fare trends, as well, according to Skyscanner.com. Fares are cheapest during early spring, late fall and during the winter months (again, with the exception of the holidays). As from London and Paris, the most expensive time to fly is during the summer months, particularly July and August.

A quick search on Google Flights shows fares are about $550 to $650 for much of spring, even heading into late June and early July. By the second week of July, however, prices spike to a little under $900, and remain there until mid August. Fall fares are similar to those of the spring, and settle back to the $550 to $700 range, with a small peak in prices for the winter holiday season.

source:
http://www.investopedia.com/articles/personal-finance/031815/when-it-cheaper-fly-new-york.asp?ad=dirN&qo=serpSearchTopBox&qsrc=1&o=40186