May Weather in Sines, Portugal

Last updated: August 27, 2025

In Sines, Portugal, the average temperature in May is a comfortable 18°C (65°F), with minimums dipping to 9°C (49°F) and maximums soaring to 32°C (90°F). During this month, you can expect 27 mm (1.1 in) of precipitation spread over about 4 days, while the average humidity levels sit at a balmy 69%.

May Temperature in Sines

In May in Sines, the average temperature is 18°C (65°F). The maximum can reach 32°C (90°F) and the minimum can be as low as 9°C (49°F). This climate makes Sines an ideal destination for travelers seeking pleasant weather and outdoor activities during this time of year.

May Weather in Sines: Daily Temperature Highs, Lows, and Averages

The chart illustrates May temperature patterns in Sines, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Sines, May typically has an average temperature of 18°C (65°F), with highs reaching up to 32°C (90°F) and lows dropping to around 9°C (49°F).

Data source: Temperature data for Sines generated using information from the Copernicus Climate Change Service.

May Precipitation in Sines

In Sines in May, the total precipitation amount is 27 mm (1.1 in) over a span of 4 days.

May Precipitation Trends in Sines

The chart displays monthly precipitation patterns in Sines, with values for each month alongside May’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how May’s conditions compare to those of other months. In Sines, May typically receives around 27 mm (1.1 inches) of precipitation spread over approximately 4 days.

Data source: Precipitation data for May generated using information from the Copernicus Climate Change Service.

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Millimeters (mm) Inches (in)

May Humidity in Sines

In Sines in May humidity is 69%. With an average temperature of 18°C (65°F), this humidity feels like a warm, damp blanket around you, making travel less comfortable and causing you to feel sticky and fatigued more quickly.

May Average Humidity in Sines

This chart illustrates the average monthly humidity levels in Sines, with May’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In May, average humidity in Sines is approximately 69%, offering insight into how humid the weather typically is during this month.

Data source: Humidity data for May generated using information from the Copernicus Climate Change Service.

May UV Index in Sines

In Sines in May, the maximum UV index reaches 10, which corresponds to a very high Exposure Category. With a time to burn of just 15 minutes, it's crucial to take precautions. For more detailed information, you can check the Hourly UV Index in Sines.

Maximum UV Index Levels in Sines for May

The chart shows the monthly maximum UV Index (UVI) for Sines in May, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In May, the maximum UV index in Sines typically reaches 10, which falls under the very high exposure category.

Data source: Sines May UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

Extreme (11+): Avoid the sun, stay in shade.
Very High (8-10): Limit sun exposure.
High (6-7): Use SPF 30+ and protective clothing.
Moderate (3-5): Midday shade recommended.
Low (0-2): No protection needed.

How May Weather in Sines Compares to Other Months

Weather in Sines varies notably across the year, with each month offering distinct climate conditions. This page compares May’s weather to other months in Sines, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in Sines, showing how May’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	11°C (52°F)	31 mm (1.2 inches)	80%	moderate
February Weather	13°C (55°F)	55 mm (2.2 inches)	73%	moderate
March Weather	14°C (57°F)	82 mm (3.2 inches)	71%	high
April Weather	15°C (59°F)	70 mm (2.7 inches)	69%	very high
May Weather	18°C (65°F)	27 mm (1.1 inches)	69%	very high
June Weather	19°C (67°F)	9 mm (0.4 inches)	67%	extreme
July Weather	21°C (70°F)	3 mm (0.1 inches)	69%	very high
August Weather	21°C (71°F)	2 mm (0.1 inches)	68%	very high
September Weather	21°C (70°F)	13 mm (0.5 inches)	71%	very high
October Weather	18°C (65°F)	45 mm (1.8 inches)	75%	high
November Weather	15°C (59°F)	62 mm (2.4 inches)	78%	moderate
December Weather	13°C (55°F)	52 mm (2.0 inches)	81%	moderate