April weather forecast
Surabaya, Indonesia

In April, the weather in Surabaya transitions further towards a drier season. There is a decline in rainfall and humidity compared to March, typical of the arrival of the dry season. The days are characterized by increased sunshine, but the comfortable temperatures persist. Recreational beach activities continue to thrill as sea temperature remains in favorable degrees, showing a slight increase from the previous month. By April's end, the wind speed decreases marginally, revealing calm outdoor conditions.

Temperature

Surabaya enters April with an average high-temperature of a still tropical 30.5°C, mirroring March's climate. A consistent nighttime average temperature of 25.6°C is maintained during April.

Heat index

For April, the heat index is estimated at a sweltering 38°C. More safety actions are required, heat exhaustion and heat cramps are probable. Long-term activity may precipitate heatstroke.
Heat index details are generally centered around shaded locations and a mild breeze. Direct exposure to sunlight could raise the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'felt air temperature', is a fusion of air temperature and moisture levels to demonstrate the sensation of heat. A person's impression of weather can be swayed by numerous aspects, among them metabolic variations, pregnancy, and activity levels. Remember, direct sunlight exposure can heighten the heat impact and might increase the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values hold great significance to children. Young individuals are typically more threatened than adults due to their reduced perspiration. Also, the larger skin surface proportionate to their small bodies and the increased heat from their activities magnify their risk.
Perspiring is the body's way of cooling down, particularly by allowing sweat to evaporate and take the heat with it. Higher relative humidity impedes evaporation, thus reducing heat dispersion from the body, culminating in a sensation of overheating. When the heat gained surpasses the body's cooling capacity, temperatures rise, signaling potential health concerns.

Humidity

In Surabaya, the average relative humidity in April is 76%.

Rainfall

In Surabaya, in April, during 21.3 rainfall days, 87mm of precipitation is typically accumulated. In Surabaya, during the entire year, the rain falls for 187.8 days and collects up to 839mm of precipitation.

Sea temperature

In Surabaya, in April, the average water temperature is 29.6°C.
Note: Temperatures between 25°C and 29°C in water are ideal for swimming, diving, and other activities, providing enjoyment and comfort for extended durations.

Daylight

The average length of the day in April is 11h and 57min.
On the first day of the month, sunrise is at 05:31 and sunset at 17:34. On the last day of April, in Surabaya, sunrise is at 05:30 and sunset at 17:22 WIB.

Sunshine

In Surabaya, the average sunshine in April is 9.1h.

UV index

The months with the highest UV index in Surabaya are January through December, with an average maximum UV index of 7. The months with the lowest UV index in Surabaya are January through December, with an average maximum UV index of 7. A UV Index estimate of 6 to 7 represents a high health risk from unsafe exposure to UV radiation for the average person.
Note: A typical high UV index of 7 in April suggests the following recommendations:
Implement preventive steps and embrace sun safety standards. Protection from skin and eye distress is compulsory. Minimize exposure to direct sunlight and seek shade from 10 a.m. to 4 p.m., when UV radiation is most intense, but remember that shade structures may not offer complete protection. Stay sun-safe with clothing that is both closely woven and worn loosely. Heads up! The reflection of sand and water notably intensifies UV rays from the Sun.