Country Overview For Costa Rica
The climate in Costa Rica is typically tropical and subtropical; dry season (December to April); rainy season (May to November); cooler in highlands. The terrain: coastal plains separated by rugged mountains including over 100 volcanic cones, of which several are major volcanoes. For San Jose in January the daily average maximum temperatures is 25°C with the average minimum 20°C, while in June the average maximum is 27°C with a minimum of 21°C. The wettest month for San Jose is January with an average of 0.0mm of precipitation falling while the driest month is January with 0.0mm falling.
HISTORICAL MONTHLY AVERAGES FOR JANUARY
The information presented below gives detailed historical monthly average weather conditions along with exceptional weather occurrences. To maintain relevance to current weather trends the displayed information has been calculated using data collected over the past two decades. The climate profile is taken from closest available data source to San Isidro.
Throughout the month of January daytime temperatures will generally reach highs of around 25°C that's about 78°F. At night the average minimum temperature drops down to around 20°C, that's 67°F.
In recent times the highest recorded temperature in January has been 39°C that's 102°F, with the lowest recorded temperature 14°C, about 57°F.
The average daily relative humidity for January is around 62%.
The Heat Index is a measure of how hot it feels when relative humidity is added to actual air temperature. From this a comfort level is calculated providing categories on how heat conditions might adversely affect someone.
Comfort Levels: Given average maximum temperatures and humidity levels generally you should not anticipate any discomfort from heat (see heat index for more information).
Estimated Hours of Sunshine per Day
We calculate sunshine hours per day using our past forecast data. For January expect the sun to shine for an average of 6 hours per day. This represents the average number of hours in the daytime that the sun is visible and not obscured by cloud e.g. the average number of hours the sun is actually out and shining. Note we calculate hours of sunshine per day using our past forecast data, not observation data, thus it is an estimate and not actual.
The average daily wind speed in January has been around 25 km/h, that’s the equivalent to about 16 mph, or 14 knots. In recent years the maximum sustained wind speed has reached 56 km/h, that’s the equivalent of around 35 mph, or 30 knots.
On average the month of January is not affected by foggy conditions.
SWIMMING AND WATER TEMPERATURE
The temperature of water an individual will feel comfortable in is very much personal preference. What feels unbearably cold to one person for a swim might be fine for another. We have created our own Swimming Water Temperature Index offering a guide to water temperature and comfort levels for swimming;
In January, for the nearest coastal location, the temperature of the sea averages around 29°C, that's 84° Fahrenheit. Our index indicates for swimming in this is considered very warm and would be enjoyed by all. With this temperature you can stay active in the water for extended periods of time without feeling uncomfortable.
YEARLY TRENDS: WEATHER AVERAGES & EXTREMES
The following charts show yearly weather trends with information on monthly weather averages and extremes.
The chart below plots the average high and low temperature for each month of the year. It also shows the maximum and minimum recorded temperatures.
The chart below plots the average number of days in any month that you can expect to see rain falling.
The chart below plots the average daily wind speed you can expect for any month. It also shows the maximum recorded sustained wind speed for each month.