May weather forecast
Cascais, Portugal

Boasting substantial sunshine hours, May graces Cascais with the authentic ambiance of spring. The beautiful weather encourages exploration around the city and its captivating ancient heritage. Rainfall continues to decline, plunging to a minimal 46mm (1.81") highlighting a significant shift from the wetter start of the year. Months moving from May towards peak summer paint a drier and sunnier picture. However, full UV protection becomes essential as the UV index begins to incline.

Temperature

With the onset of May, Cascais experiences a subtle temperature shift, with the average high-temperature moving from a refreshing 18°C (64.4°F) in April to a pleasant 21°C (69.8°F). The average low-temperature of 13°C (55.4°F) is witnessed in Cascais during May.

Rainfall

In Cascais, in May, it is raining for 9 days, with typically 46mm (1.81") of accumulated precipitation. In Cascais, during the entire year, the rain falls for 116 days and collects up to 841mm (33.11") of precipitation.

Sea temperature

In Cascais, in May, the average water temperature is 17.4°C (63.3°F).
Note: For most people, a water temperature of 17.4°C (63.3°F) is not conducive to enjoyable swimming. Breathing control becomes harder as the water temperature dips below 21°C (69.8°F).

Daylight

The average length of the day in May is 14h and 17min.
On the first day of the month, sunrise is at 06:39 and sunset at 20:30. On the last day of May, in Cascais, Portugal, sunrise is at 06:14 and sunset at 20:56 WEST.

Sunshine

The average sunshine in May in Cascais is 9h.

UV index

The average daily maximum UV index in May is 8. A UV Index reading of 8 to 10 represents a very high health hazard from exposure to the Sun's UV radiation for the average person.
Note: In May, the maximum UV index of 8 translates into these guidelines:
Take extra precautions. Fair-skinned individuals may get burned in less than 10 minutes. Limit direct sun exposure especially between 10 a.m. and 4 p.m., when UV radiation is at its peak. However, keep in mind that shade structures may not provide full sun protection. For optimum UV protection, wear sun-resistant attire complemented with a hat and quality shades.