There are two distinct seasons in Nosara: hot & wet and hot & dry. Both have their pros and cons.

Dry Season: The dry season is the biggest tourist season, which basically runs from December to April. During that time, there will be almost no precipitation. That is why our tourism is so good. You can literally plan your trip five years in advance and it’ll be sunny when you get here during those months. In the beginning of that season, usually around the end of December until about the middle of February we get daily offshore winds that leave many of our deciduous trees naked. These winds can be strong at times and can break tree limbs and leave us without power for a couple of hours. I would say we average 10-15 days/year when the winds are over 25MPH. The surfers tend to like the dry season because the surf is much better with the offshore winds cleaning up the waves. At the end of February some of the trees start to get their new leaves. March and April are our hottest months when it will get in the mid 90’s (34-35C) and our roads will be plenty dusty. A nice occurrence in March is when many of the trees flower and you will see yellow, pink and purple dotting the surrounding hills and mountains.

Green Season: When the rain does arrive it is quite glorious. This can be anytime from late March to late May but usually in the middle to end of April. When it does finally rain, everything turns lush green within a week and the birds and animals appear. There is a big difference in the morning music put on by the singing birds. The cattle fields turn from yellow to green and the cows go from scrawny to plump. When many people hear ‘rain season’, they think ‘monsoon season’. That is not the case. Many year round Nosara residents prefer the rain season for various reasons. A typical rain season day would be sunshine until about 10:00am when a few clouds would start appearing. In the mid afternoon you might have a 15 minute shower followed by more sun and usually a spectacular sunset and maybe another shower in the evening or night. Days like this are very common in May and June, while in July we sometimes get an ‘Indian Summer’ with less seasonal rain. The two months when the rain is usually the strongest are September and October. The pattern is generally the same… but when it rains, it pours! Our heaviest rains come when we get the outer bands of hurricanes/tropical storms that begin to form in the Caribbean. While we do not get the wind, we do get some rain. If it rains hard for several days from one of these hurricanes, the Nosara River has been known to flood for hours at a time. The river is tidal, so this happens at high tide. As the tide goes out, the water drains. Keep in mind, the stronger the rain, the worse the roads. November and December tend to be very nice months as the rain starts to taper off, but the landscape is still green.

The trade off is that during dry season the beach and ocean are gorgeous while the landscape looks more brown and the fields yellow while in the rain season the landscape is a lush, green jungle but the Pacific is not as turquoise because of the river run off. Both seasons are very enjoyable.

http://costa-rica-guide.com/travel/weather/weather-map-rainfall/