Peak Season:
The dry season from late November to late April is the best time to book flights to Costa Rica. The weather is extremely pleasant for exploring the forests or laying on the beach. Flights to Costa Rica are more expensive between these months as it's the main tourist season, so expect big crowds and more expensive hotel rates. If you book your flights to Costa Rica early enough you can sometimes find deals.
Off Season:
Winter is considered between May to November, which is also the rainy season in Costa Rica. However the temperatures are generally mild and pleasant unless you're up in the mountains. You can find the cheapest flights to Costa Rica during the winter, and you'll find much cheaper accommodation too. Avoid flights between September and October as they are the rainiest months and some hotels shut down, although you will find cheap flights to Costa Rica.
The winter offers cheap flights to Costa Rica, so if you book a month or two in advance you can save a lot on your flight tickets. During the summer is a lot more expensive for flights to Costa Rica, especially if you want to visit the main tourist destinations. If you can be flexible with your dates then you'll find cheap flights to Costa Rica without too much trouble, and although the rainiest months are the cheapest, you will find some hotels closed. Sitting on either side of the plane should reward you with spectacular views of lakes and beaches, however this is dependent on the weather.
Flights from London (All airports) to San Jose, Costa Rica - 13 hours 40 minutes
Flights from Manchester to Costa Rica - 15 hours 40 minutes
Flights from Birmingham to San Jose, Costa Rica - 10 hours 45 minutes
Flights from Glasgow to Costa Rica - 18 hours 30 minutes
British Airways, Air Canada, Aeromexico and Delta Air Lines all operate flights to Costa Rica. Depending where you want to fly to will depend on who your airline will be. British Airways offer complimentary food and drinks throughout the flight so you can take advantage and get the best value for your money if you request several beverages. The best bet is to compare each airline for fees for checked in baggage etc and then decide which is the most beneficial for you.
San Jose, Costa Rica:
The airport is located around 17km from the city of San Jose, and there are a couple of different methods to transport between the two. Outside of the airport you can get a local bus directly downtown and there is storage under the bus for luggage. It's the cheapest option to get downtown and you can get a taxi from downtown if you need to get elsewhere. When getting a taxi, make sure you agree on a fee before getting in as a lot of taxis charge up to twice the normal amount to tourists, so finding out an average price beforehand is helpful.
Daniel Oduber Quirós, Costa Rica:
Also known as The Liberia International Airport, Daniel Oduber is located just a few miles away from the closest beach and only 12km from the city of Liberia, making it convenient for your flights to Costa Rica. Airport shuttles are the easiest way to travel to the city, with the added benefit of taking you directly to your hotel or destination, as opposed to the public buses which are restricted on exactly where to drop you off. Due to legislation, if you want an airport shuttle you must reserve it in advance, so once you've booked your flight to Costa Rica it's advisable to arrange a shuttle as soon as you've organised your accommodation.