April weather forecast
Manaus, Brazil

The pace of travel begins to slow in April due to less sunshine hours. Weather becomes marginally cooler, yet maintains its tropical appeal. Sunshine hours decline to three hours and rainfall remains relatively high. Visitors during this period should remember to carry their umbrellas to negotiate the intermittent downpours without disrupting their plans. Amazon boat tours present an enchanting sight with lush green forest under overcast skies.

Temperature

Manaus, Brazil, registers an average high-temperature of a still hot 30.7°C (87.3°F) with the arrival of April, showing minor deviation from the preceding month. During April, the nighttime temperature in Manaus averages of 23.3°C (73.9°F).

Heat index

April's average heat index is calculated to be a scorching 42°C (107.6°F). Implement additional cautionary measures, heat cramps and heat exhaustion could occur. Prolonged activity might induce heatstroke.
Be informed that the heat index values are oriented around shady conditions and gentle breezes. Direct sunlight might cause an increase of up to 15 Fahrenheit (8 Celsius) degrees in the heat index.
Note: The heat index, also known as 'apparent temperature' or 'felt air temperature', is found by incorporating humidity levels into the air temperature measurement. The effect is experienced differently by individuals, hinging on unique characteristics such as body mass, stature, and level of activity. Remember, direct sunlight exposure can heighten the heat impact and might increase the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are essentially critical for children. Kids are usually more vulnerable than adults, given their lesser sweating ability. Along with their larger skin surface relative to their small stature and the excess heat due to their activity, their risk is amplified.
Evaporation of sweat is the main factor behind the cooling effect of perspiration in the human body. A higher relative humidity affects normal body cooling by reducing the evaporation rate, subsequently lowering the rate at which the body cools and increasing the perception of heat. Accumulating heat beyond the body's cooling measures leads to rising temperatures and potential ailments.

Humidity

In April, the average relative humidity is 87%.

Rainfall

In Manaus, during April, the rain falls for 18 days and regularly aggregates up to 311mm (12.24") of precipitation. Throughout the year, in Manaus, there are 160 rainfall days, and 2307mm (90.83") of precipitation is accumulated.

Daylight

In Manaus, the average length of the day in April is 12h and 2min.
On the first day of April, sunrise is at 06:01 and sunset at 18:06. On the last day of the month, sunrise is at 05:57 and sunset at 17:57 -04.

Sunshine

The average sunshine in April is 3.7h.

UV index

The months with the highest UV index in Manaus are January through May, August through December, with an average maximum UV index of 12. A UV Index of 11, and more, symbolizes an extreme threat to health from unsafe exposure to UV radiation for average individuals.
Note: The maximum daily UV index of 12 during April translates into the following directions:
Execute all vital precautions. Preventing sun damage is of utmost importance. The time between 10 a.m. and 4 p.m. is when UV radiation is at its peak. Limit exposure to direct sunlight during these hours. For excellent sun protection for the eyes, ears, face, and neck, consider a wide-brim hat. Sunscreen of at least SPF 30 should be applied generously and reapplied often on overcast days, especially post swim or outdoor exercise.