September weather forecast
Caldera, Costa Rica

September, the first month of the autumn in Caldera, is still a warm month, with an average temperature fluctuating between 23.2°C (73.8°F) and 28.9°C (84°F).

Temperature

As August turns into September, the average high-temperatures rest at a still moderately hot 28.9°C (84°F), showing a minor variation from the prior month. During September, Caldera sees a mean low-temperature of 23.2°C (73.8°F).

Heat index

The heat index in September is appraised at a fiery hot 35°C (95°F). Adopt additional preventive measures, heat cramps and heat exhaustion are potential outcomes. Prolonged activity may trigger heatstroke.
Thinking about the heat index, one should account for its values in shaded areas with gentle breezes. Facing direct sunlight may hike up the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'apparent temperature', ties air temperature with relative humidity to produce the perceived temperature sensation. Elements such as metabolic variations, pregnancy, and physical exertion can shape one's weather perception. One's exposure to direct sunlight has the potential to intensify the heat sensation, increasing the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are particularly relevant to children. Youngsters generally face more threats than adults given their lesser ability to sweat. Coupled with their larger skin surface relative to their small bodies and higher heat production due to their activities, they are more endangered.
To combat high temperatures, the human body perspires and relies on sweat evaporation for cooling. During conditions of high air temperature and humidity (high heat index), the body's ability to perspire is inhibited, increasing the sensation of warmth. Overheating dangers loom when the body's heat release mechanisms are overshadowed by excessive gain.

Humidity

The average relative humidity in September in Caldera is 82%.

Rainfall

In Caldera, in September, during 27.7 rainfall days, 193mm (7.6") of precipitation is typically accumulated. In Caldera, during the entire year, the rain falls for 218.6 days and collects up to 1456mm (57.32") of precipitation.

Daylight

In September, the average length of the day is 12h and 11min.
On the first day of September, sunrise is at 05:29 and sunset at 17:47. On the last day of the month, sunrise is at 05:27 and sunset at 17:29 CST.

Sunshine

The average sunshine in September is 8.7h.

UV index

The months with the highest UV index in Caldera are January through September and December, with an average maximum UV index of 7. A UV Index value of 6 to 7 symbolizes a high health risk from unprotected exposure to Sun's UV rays for the average person.
Note: In September, the average maximum UV index of 7 translates into the following recommendations:
Take precautions against overexposure. Protection against sun damage is needed. Avoid direct Sun exposure and stay in the shade between 10 a.m. and 4 p.m., a time when UV radiation is most intense, noting that not all shade structures offer full protection. Shield yourself from the harmful effects of UV radiation with sun-protective attire, a hat, and quality sunglasses.