Yes… and no.
Of course the sunny season! … Ehmmm! not all the time. It really depends on which volcano you want to see the sunny season is not always sunny and the rainy season is not always rainy.
Let’s take for instance the month of September… Best time to see Arenal, Turrialba and Irazú. Rainy in the Central Valley and the Pacific Coast. And I mean… rainy!! Floods and everything! However the Caribbean is as sunny and calm as you can imagine! A great time to go to that side and the volcanoes on that side…
Another: December, on a clear day, great to see Rincon, Poas and Irazu. Forget about Arenal… You would have to wait until March to see it again… But the pacific side of the country is sunny and gorgeous… a bit windy though.
And let me explain you why…
In the sunny season we have the Caribbean trade winds coming in the country. They come in filled up with humidity and pour over the Caribbean plains… the cloud gets to the mountains (Volcanoes) gets stucked there… and then, the rest of the country, remains sunny… with no clouds (They are stuck at the tops of the volcanoes… fog up on the tops).
In the rainy season a different phenomena happens, and the humidity turns into rain quickly… and then, it turns out that the tops of the mountains look clear and beautiful.
So, let’s see… Out of the volcanoes, the best time to visit is:
Poas. March through April, October, November. (December is a question mark… but usually at the end of the year it looks great!)
Irazu: January to April, September and October. (Just like Poas… great at the end of the year!)
Turrialba: January to April, September and October.
Arenal: March through July, September and October.
Rincón: December through May.
MIravalles: December through May.
Remember though, this is just a guideline… We are in the tropics, the most classical conundrum for any weather forecast!
Written by Olga Green for 2 Costa Rica Travel
About the author: Olga Green has been in the travel industry for more than twenty five years, She was a naturalist tour guide in Costa Rica for eighteen years, a product manager and a travel writer for several companies in and out of Costa Rica.