Costa Rica is very mountainous, creating a climate for everyone. Lacking a snowy winter, the weather is for most people highly desirable. The weather in the highlands (dubbed the name "eternal spring" because of it's cool mild temperatures year round) and the summer weather along both coasts has made this one of the most attractive climates in the world. Costa Rica's temperature only varies 2 degrees Celsius from Summer to Winter. Costa Rica, however, has a wide range of temperature and climate zones because of the different elevation and precipitation levels you find here.
|Situated at just ten degrees latitude north of the equator, this tropical nation receives sunlight from a nearly overhead angle almost year-round. Also, day length does not vary more than an hour in fluctioation throughtout the year, resulting in 12hrs of daylight +/- an hour.
Theannual temperatures remain quite constant for any particular place in the country at a given hour.The temperature in San José at noon averages 25.5º C in June and 23.5º C in December which is hardly a significant difference.During any 24-hour period there is a somewhat greater range of temperatures experienced between the daily high and low, although this, too, at an average of about 8º C, is relatively small compared to the many temperate zone areas. With generally consistent temperatures found at any given location, the most important variable in annual weather patterns becomes precipitation.
- Arenal offers spring year-round
- The Caribbean and Central and South Pacific regions enjoy lush jungle
- Talamanca and Monteverde have rolling fog mountaintops
- Northern Guanacaste enjoys a dryer climate, especially during the dry season Dec - May with constant Breezes form the North aka "Papagayo Winds"
Costa Rica’s seasons are differentiated by rainfall rather than temperature change.
"Rainy Season" Typically, the rainy season is from May until November, however September and October are the rainiest months. The rainy season in most places experiences clear mornings with rain throughout the afternoon which makes it also a great time to visit Costa Rica, Tip: Incredible sunsets
"Dry Season" November to April are the driest months (especially in Guanacaste)
The dry season still experiences occasional rainfal especially in the South Pacific and Caribbean coastal regions
"Winter" Jun - Aug (the beginning of the rainy season)
"Summer" Dec - Mar (dry season) also dependent where you are
Depending on Elevation and Location, Climates differ throughout Costa Rica; but as a general rule:
- the coastal regions are hoter and moister with Guanacaste (North Pacific) as an exception as it offers multiple seasons. Guanacaste actually is very dry during the dry season.
- the lower highlands offer spring like temperatures
- the highlands enjoy a cooler climate with more rainfal and or moisture in the cloud forests
During the rainy season, rainfall is usually a daily occurance. The massive amounts of rain are caused by the trade winds that blow in that time of year, and the terrain of the country. The difference in temperatures between the air and the land cause the moisture in the air to release (as rain). As the winds continue to the middle of the country, the air encounters the mountains and has to travel upward to cross the peaks. When this happens, the temperature of the air drops, causing it to release more moisture in the form of rain. Also, the temperatures on the ground vary accordingly. In the higher elevations and central valley, temperatures remain almost a constant temperature. San Jose has been said to have an “eternal Spring” because of the mild temperatures year round.
When discussing the dry season, typically this begins in November and continues through May. This dry time period is most noticeable in the northwest and central valley regions. Long story short, the trade winds that have caused the rains in the eastern section, have now dried out and continue west. The dry air absorbs and moisture in the Pacific region, and dries out everything in its path. The dry air continues to blow with a lack of clouds (no moisture) and the sun beats down, creating hot, dry days in the Northern Pacific region. As you head south along the Pacific coast, this trend is not as severe. The winds that dry out the Northern Pacific region, are blocked by the Talamanca Mountain Range, allowing moist air to come inland, and create some rain fall in this area.
The Carribean side of Costa Rica varies slightly from the Pacific side. Typically, this side receives more rainfall annually than the other portion of the country...sometimes upwards of 3500-4000mm per year. The Carribean area also experiences a dryer season in January through the end of April, but not nearly as dry as the Pacific, and typically rainfall occurs throughout the year.
So, what causes the rainy season in Costa Rica? The change in the Earth's axis plays a major role, as does other natural meteorological occurances. The Pacific side tends to get more rainfall as the trade winds shift north, and allow the moisture filled breezes from the Pacific back onshore. As the winds from both coasts reach each other, they tend to release their moisture. Other factors include hurricanes/tropical storms, tropical depressions, and general weather conditions.