May weather forecast
Castanhal, Brazil

The last month of the autumn, May, is a hot month in Castanhal, Brazil, with temperature in the range of an average high of 30.3°C (86.5°F) and an average low of 22.6°C (72.7°F).

Temperature

The weather during May records an average high-temperature of a tropical 30.3°C (86.5°F), closely mirroring the preceding month. In May, Castanhal records an average nighttime temperature of 22.6°C (72.7°F).

Heat index

The heat index value during May is calculated to be an extremely hot 42°C (107.6°F). Take more caution, heat exhaustion and heat cramps may occur. Long-lasting activity may cause heatstroke.
Be aware that heat index ratings are designed for shaded locations and minor breezes. Heat index values may surge by up to 15 Fahrenheit (8 Celsius) degrees in the presence of direct sunlight.
Note: The heat index, also known as 'apparent temperature' or 'real feel', blends air temperature and moisture content to represent the felt temperature to humans. The impact of temperature is individual, as people's perception of weather may change based on their body mass, height, and physical activity. You should know that direct sun exposure can heighten weather effects, potentially elevating the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely vital to babies and toddlers. Young children are generally more endangered than adults, as they usually less sweat. And also, due to larger skin surface relative to their small bodies and higher heat production as a result of their activity.
The innate cooling system of the human body revolves around perspiration, with the evaporation of sweat being central to this process. When the level of relative humidity is elevated, evaporation diminishes, causing more warmth to be retained in the body than in dry air. When the body's heat gain surpasses its removal capacity, body temperature starts to climb, leading to potential heat-related ailments.

Humidity

In May, the average relative humidity in Castanhal is 91%.

Rainfall

In May, in Castanhal, the rain falls for 30.7 days. Throughout May, 176mm (6.93") of precipitation is accumulated. In Castanhal, Brazil, during the entire year, the rain falls for 332.9 days and collects up to 1589mm (62.56") of precipitation.

Daylight

In May, the average length of the day is 12h and 4min.
On the first day of the month, sunrise is at 06:06 and sunset at 18:10. On the last day of May, sunrise is at 06:07 and sunset at 18:11 -03.

Sunshine

In May, the average sunshine in Castanhal is 7.1h.

UV index

The months with the highest UV index are May, July, September through November, with an average maximum UV index of 7. A UV Index value of 6 to 7 symbolizes a high health vulnerability from unsafe exposure to UV radiation for the ordinary person.
Note: The maximum daily UV index, 7 in May, converts into the following recommendations:
Beware of overexposure. Fair-skinned individuals risk burning in less than 20 minutes. Try to minimize direct Sun exposure between 10 a.m. and 4 p.m., the peak period for UV radiation. Also note that objects like parasols or canopies might not provide complete sun protection. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.