I think that the best way to find the cheapest flights is to sign up at one of the websites specialized in airfare deals alerts. However I think you can buy the cheapest tickets for autumn - but it also depends when you buy them..
25:00 hrs
The cheapest time of the year to fly to El salvador is from February to March and then again in May, and then from August to October.
about February =)
spring break
when the kids are at school
March
during Ausgust or October
ALL YEAR LONG
There is no such cheapest time of the year. You just has to book well in advance for your flights and you get a best deal. Say almost one or two months in advance and try to fly on Saturday you will get chap air deals.
I think... November
The cheapest time to fly to The Philippines is any time that isn't within 2 weeks of any holiday or any major vacation time such as summer, mid winter, or late spring. Your best bet is to book your flight a long time such as 6 months in advance, and sometime in the fall.
January and February are considered out of season and are generally the lowest cost.
If you want to fly cheap book your seats 6 months earlyer