Eyes on Costa Rica and Weather Records - December and Year 2020

 During December, visits to this blog were received from the following 19 countries:

For all years, the total number of identified countries from which visits have been received remains at 130.

The following is a summary of the weather for the month and year in the area where we live:

As if a switch had been thrown, December 4 marked the beginning of the dry season. There was a hiccup with heavy rain on December 30 but otherwise sunny and partly cloudy skies prevailed. Temperature averages in December were pretty much like those in previous years.

For the year as a whole, rainfall was the real story. A brief summary for the entire year in the area where we live is as follows:

However, as the following graph illustrates, the amount and timing of rainfall in 2020 was significantly different from that in 2018 and 2019.

The patterns of rainfall in 2018 and 2019 were about the same - the monthly amounts following a distinct "M"-shaped curve each with a significant dip in the middle of the dry season. The dip is characteristic of a mini-summer or "verano" which typically occurs in the middle of the Costa Rican rainy season. In contrast, there was no such dip in 2020.

There were more rainy days in 2020 (185 days) than in 2018 (151 days) or 2019 (142 days) and the total amount of rainfall in 2020 (116.1 inches, 2949 mm) was greater than in 2018 (78.54 inches, 1995 mm) or 2019 (64.14 inches, 1629 mm). But this pales in comparison to the amount of rainfall encountered by friends who live in the southern zone of Costa Rica and who recorded over 320 inches (8218 mm) of rain in 2020.

Whether 2020 was an aberration or an indication of climate change events which are on the way remains to be seen.

(Click on any image to enlarge)

Weather Review - 2015

Here is a temperature chart and a rainfall chart which illustrate weather conditions over the course of the last year in the Atenas region of Costa Rica. More particularly, and except for a brief period in early October, they illustrate the conditions where we normally live in a neighborhood called Vista Atenas which is a short distance west of the town of Atenas. For the brief period in October, we were house and cat sitting at the home of friends in a neighborhood called Las Cumbres – a short distance east of the town. The significance of east v. west is revealed by the temperature chart.

As the crow flies, the Las Cumbres location is about 3.7 miles (6 km) from our Vista Atenas location. But, the elevation is about 560 feet (170 m) lower. In Costa Rica, lower altitudes are generally reflected by higher daytime high temperatures and that is borne out by the temperature spike circled in red on the above chart.

As I think I have said before, Costa Rica is a country of microclimates. A few miles one way or the other and a few hundred feet up or down can make a significant difference. If you choose to live in Costa Rica for any length of time, then you should carefully choose the location. Where we live in Vista Atenas, the year 'round daytime highs and overnight lows are comfortable. Neither heating nor air conditioning is required. On rare occasions, heat and humidity can combine to produce a marginally uncomfortable "feels like" temperature. In 2015, that may have happened three or four times.

 

Costa Rica has two seasons: a wet or “green” season and a dry season. In our area, the dry season normally extends from about mid November of one year to late April or early May of the next. The above chart shows virtually no rain until late April and, excluding an exceptional one day deluge, almost no rain in December. However, in 2015, the wet season was drier than normal. Total rainfall was about 10 inches less than 2014. If the December deluge never happened, then the shortfall would be almost 13 inches less. It must be el niño at work – or maybe even climate change.