May weather forecast
Surabaya, Indonesia

May in Surabaya marks the real advent of the dry season with minimum rainfall recorded at 47mm (1.85"). Encouragingly, sun lovers will enjoy the steadily increasing sunshine hours. The weather remains warm, but the declining humidity levels create a charmingly comfortable atmosphere. As the wet season's receding show, sea temperatures continue to drop while maintaining ideal swimming and water sport conditions. By the end of the month, residents and visitors can look forward to more sunshine and less rainfall.

Temperature

May experiences an average high-temperature of a still tropical 30.8°C (87.4°F), barely different from April's 30.5°C (86.9°F). An average low-temperature of 25.7°C (78.3°F) is recorded during the nights in May in Surabaya.

Heat index

The heat index value for May is evaluated at a fiery hot 38°C (100.4°F). Take more preventive steps, risk of heat exhaustion and heat cramps is elevated. Long activity may culminate in heatstroke.
Heat index guidelines indicate values are for light wind scenarios and shaded regions. Being under direct sunlight might amplify the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'real feel', stands as a testimony to how temperature and humidity combine to impact our sense of warmth. The impact of weather is individual, with diverse individuals experiencing it differently due to variations in body mass, height, and activity levels. Understand that direct sun rays can influence the weather's impact, leading to an increase in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely significant for children. Children frequently underestimate the necessity to rest and hydrate. Thirst is a late sign of dehydration - thus, it is vital to stay hydrated, particularly during lengthy physical exercises.
Perspiration is the human body's physiological response to high temperatures and is an attempt to lower body temperature through evaporation of sweat. Elevated relative humidity diminishes evaporation, thereby reducing the body's ability to shed heat and creating a feeling of being too warm. Should the body fail to balance its heat gain, the escalating temperature poses health challenges.

Humidity

In May, the average relative humidity in Surabaya is 74%.

Rainfall

In May, the rain falls for 14.1 days. Throughout May, 47mm (1.85") of precipitation is accumulated. Throughout the year, there are 187.8 rainfall days, and 839mm (33.03") of precipitation is accumulated.

Sea temperature

In Surabaya, in May, the average water temperature is 29.5°C (85.1°F).
Note: Water temperatures between 25°C (77°F) and 29°C (84.2°F) are ideal for all water activities, offering enjoyment without causing discomfort over extended periods.

Daylight

The average length of the day in May is 11h and 47min.
On the first day of the month, sunrise is at 05:30 and sunset at 17:21. On the last day of May, in Surabaya, Indonesia, sunrise is at 05:34 and sunset at 17:18 WIB.

Sunshine

In May, the average sunshine in Surabaya is 9.5h.

UV index

January through December, with an average maximum UV index of 7, are months with the highest UV index in Surabaya. The months with the lowest UV index 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 exposure to the Sun's UV radiation for the ordinary person.
Note: A maximum UV index of 7 in May translates into the following recommendations:
Evade overexposure. Individuals with fair skin risk burning in under 20 minutes. The Sun's UV radiation is most intense from 10 a.m. to 4 p.m. Try to avoid direct sun exposure during these hours. Select sunglasses that boast both UVA and UVB protection to limit the adverse effects of the sun on the eyes. Be on guard! The reflective nature of sand and water boosts UV exposure.