São Luís experiences a significant dip in rainfall in
June, moving further away from the wet season. This reduction in rainfall, to 173mm (6.81"), is coupled with marginally cooler average sea temperatures. Daylight continues to clock at 12 hours for the sixth consecutive month. With a reduced UV index of 10, June establishes the onset of the dryer season, nudging São Luís's weather towards a comparatively less humid and cooler phase.
Temperature
São Luís's shift from
May to June is accompanied by an average high-temperature of a still tropical 30.4°C (86.7°F), a slight deviation from 30.1°C (86.2°F). The mean low-temperature during June nights in São Luís,
Brazil, is a pleasant 22.9°C (73.2°F).
Heat index
The heat index in June is appraised at a blistering 41°C (105.8°F). Adopt special protective actions against heat exhaustion and heat cramps. Long-duration activity risks heatstroke.
Heat index values are typically calculated for conditions of shade and a light breeze. The heat index may experience an enhancement of 15 Fahrenheit (8 Celsius) degrees under direct sunlight.
Note: The heat index, also known as 'real feel' or 'felt air temperature', is an estimation of the warmth sensation when considering humidity levels. The impression of weather on a person can be swayed by additional aspects, including metabolic variations, pregnancy, and activity levels. The sun, when shining directly, can have a significant impact on the perceived temperature, increasing the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are largely significant for babies and toddlers. Juveniles often do not understand the need to recuperate and rehydrate. Thirst is a delayed symptom of dehydration - hence, it is vital to maintain hydration, particularly during ongoing physical activities.
Perspiring is the body's way of cooling down, particularly by allowing sweat to evaporate and take the heat with it. An increase in relative humidity hinders the body's normal cooling function by reducing evaporation, thereby decreasing the rate of body cooling and enhancing the sense of warmth. The body faces dehydration threats when its cooling efforts are outpaced by excessive heat gain.
Humidity
In June, the average relative humidity in São Luís, Brazil, is 86%.
Rainfall
In June, the rain falls for 13 days. Throughout June, 173mm (6.81") of precipitation is accumulated. Throughout the year, there are 130 rainfall days, and 2290mm (90.16") of precipitation is accumulated.
Sea temperature
In São Luís, the average seawater temperature in June is 28.3°C (82.9°F).
Note: Swimming, diving, and other activities in water temperatures between 25°C (77°F) and 29°C (84.2°F) are thought to be quite enjoyable and satisfying for extended periods, with no discomfort.
Daylight
The month with the shortest days in São Luís is June, with an average of 12h and 0min of daylight.
On the first day of June in São Luís, sunrise is at 05:55 and sunset at 17:54. On the last day of the month, sunrise is at 06:01 and sunset at 18:00 -03.
Sunshine
In June, the average sunshine is 7.1h.
UV index
The months with the lowest UV index in São Luís are June and
July, with an average maximum UV index of 10. A UV Index estimate of 8 to 10 represents a very high threat to health from unsafe exposure to UV radiation for the average person.
Note: The daily maximum UV index of 10 in June interprets into the following advice:
Protection should always be a priority. Skin and eyes are vulnerable without it. Remember that UV radiation from the Sun is strongest between 10 a.m. and 4 p.m. Make an effort to limit direct sun exposure during this time. Sunglasses providing both UVA and UVB protection are non-negotiable on sunlit days. Apply liberally and reapply a broad-spectrum sunscreen of SPF 30+ every two hours, and promptly after any outdoor workout or a swim. Caution! The Sun's UV intensity grows with reflections off sand and water.