June weather forecast
San Juan, PR

June in San Juan is characterized by peak summer conditions, with average high temperatures reaching 84.2°F (29°C). The sun dominates the sky for an impressive 10.9 hours per day, yet rainfall remains moderate at 0.71" (18mm). Sea temperatures also rise to an appealing 82.8°F (28.2°C), encouraging beachside relaxation amidst the season’s swelter. Despite an increase in humidity, the wind speed remains consistent, providing much-needed respite. These conditions underscore June as a quintessential summer month.

Temperature

San Juan's shift from May to June is accompanied by an average high-temperature of a still warm 84.2°F (29°C), a slight deviation from 82.4°F (28°C). San Juan observes an average low-temperature of 78.3°F (25.7°C) during the slightly cooler nights of June.

Heat index

The heat index value for June is estimated at a fiery hot 95°F (35°C). Heightened safety actions are necessary, heat cramps and heat exhaustion are probable. Persistent activity may lead to heatstroke.
Be advised, the heat index considers values for conditions in shade and with a light breeze. The heat index could see an increase by 15 Fahrenheit (8 Celsius) degrees under direct sunshine.
Note: The heat index, also known as 'feels like' or 'felt air temperature', gauges the sensation of temperature factoring in the air's moisture content. The influence of weather is personal, differing among a variety of individuals based on differences in body mass, stature, and the level of physical activity. Sunshine, when direct, has the potential to intensify weather effects, leading to an increase in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are primarily vital for children. Children often do not understand the need to rest and hydrate. Thirst is a late manifestation of dehydration - therefore, it is essential to stay hydrated, particularly during prolonged physical activities.
Evaporation of sweat is the main factor behind the cooling effect of perspiration in the human body. With high air temperature and humidity (high heat index) conditions, sweat production is restricted, leading to an amplified perception of heat. Should the body fail to balance its heat gain, the escalating temperature poses health challenges.

Humidity

May through July, with an average relative humidity of 79%, are the most humid months.

Rainfall

In June, the rain falls for 10.3 days. Throughout June, 0.71" (18mm) of precipitation is accumulated. Throughout the year, there are 159.9 rainfall days, and 12.01" (305mm) of precipitation is accumulated.

Ocean temperature

In June, the average ocean temperature in San Juan is 82.9°F (28.3°C).
Note: Between the temperatures of 77°F (25°C) and 84.2°F (29°C), water is considered very warm, providing pleasure in water activities without discomfort over lengthy periods.

Daylight

With an average of 13h and 12min of daylight, June has the longest days of the year.
On the first day of the month, sunrise is at 5:47 am and sunset at 6:57 pm. On the last day of June, sunrise is at 5:51 am and sunset at 7:04 pm AST.

Sunshine

June has the most sunshine of the year, with an average of 10.9h of sunshine.

UV index

The months with the highest UV index are April through November, with an average maximum UV index of 7. A UV Index of 6 to 7 symbolizes a high health risk from unprotected exposure to Sun's UV rays for the average person.
Note: The maximum UV index of 7 during June leads to these instructions:
Persist with safeguards and heed sun safety doctrines. Keeping sunburn at bay is of prime importance. The Sun's UV radiation is most powerful between 10 a.m. and 4 p.m. To the extent possible, limit exposure to the direct sun during these hours. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects. Watch out! Sand and water enhance the UV exposure you receive.