SkyTeam airlines Delta, KLM and Air France partner with Air Baltic for discount flights to the Baltic nations. JFK to Tallinn, Estonia is as low as $417 through online travel agencies and $457 directly on KLM. Riga, Latvia is $489 round trip on KLM, but TravelMerry.com has oneworld flights to Riga priced in $390s.
Departure dates are primarily January to March, before fares rise to $500-$600s.
KLM Airlines/ Air Baltic New York JFK – Amsterdam AMS – Tallinn, Estonia TLL – AMS – JFK
KLM Airlines/ Air Baltic New York JFK – Amsterdam AMS – Riga, Latvia RIX – AMS – JFK
These Baltic destinations are significantly lower priced for some travel dates when searching Momondo.com and Skyscanner.com meta-search for online travel agency discount fares. Tallinn, Estonia had limited discounts of less than $20 for dates I checked, however, Riga, Latvia came up for $397 with Oneworld flights to Helsinki.
TravelMerry.com ticket British Airways codeshare JFK-HEL Finnair flight outbound and LHR-JFK American Airlines inbound with Finnair HEL-TLL and Air Baltic TLL-LHR
New York JFK – Helsinki HEL – Riga, Latvia RIX – London LHR – New York JFK
$395.86 round trip Sat Feb 18 – Sun Feb 26