Weather in Algarve in May

How May compares

May is the 6th warmest month of the year in Algarve and ranks 73rd of 134 destinations we compare for May - see where else is hot in May. Within Portugal it is 5th of 13 (Portugal in May). Against London's average high of 16.6°C in May, Algarve is 5.9°C warmer by day and 6.3°C warmer at night.

Daytime and night-time in May

The typical May day in Algarve peaks at 22.5°C, but that is an average: the warmest 10% of days reach 27.2°C or more. Roughly 1 in 4 days top 25°C and 1 in 33 pass 30°C. Nights average 14.6°C; one night in ten drops to 11.8°C or lower, so pack a layer for evenings - it is genuinely cool after dark. Between 1991 and 2020 the hottest May day here reached 35.7°C (2012-05-15) and the coldest night 8.0°C (2013-05-01).

Rain in May

Some rain (4-8 rainy days): about 6 days with 1 mm or more, 35 mm in total. Year to year it varies a lot - the wettest May was 2016 with 113 mm, the driest 2006 with 0 mm. Humidity averages 68%.

Sea temperature in May

The sea averages 17.2°C - too cold for most (under 18°c). Depending on the year it ranges from 16.3°C to 18.2°C. For the warmest sea here, come in August (20.7°C).

Sunshine and daylight

Around 8.4 hours of sunshine a day (estimated from cloud cover), 14.0 hours of daylight: the sun rises about 06:24 and sets about 20:33 local time in mid-May. Average cloud cover is 40%.

Is May a good time to visit Algarve?

It is a reasonable choice: warm days. The best months for Algarve on our scoring are July, August, June; months averaging 25°C or more: Jun, Jul, Aug, Sep.

Warm afternoons, without reliable summer heat

The Algarve is noticeably warmer than London in May, with average daytime highs 5.9°C higher. That makes it a reasonable choice for outdoor lunches and spending time by the coast without needing intense heat. Days reach 25°C about 25% of the time, while 30°C is much less common, at 3%. You may get a hot spell, but it should be a bonus rather than the basis of your plans. Keep the middle of the day flexible when it feels warmer, and pack sun protection. May suits travellers who prefer comfortable warmth; those wanting consistently hotter weather should look towards summer.

Plenty of daylight, with room for rain

Around 8.4 hours of sunshine within 14.0 hours of daylight gives you plenty of scope to spend time outdoors, but it does not promise uninterrupted blue skies. There are about 6 rainy days, so a light waterproof is more useful than assuming every day will be dry. Keep beach plans movable and use the brighter spells rather than committing your whole stay to sunbathing. Rain need not rule May out, though travellers who would be disappointed by any wet weather may find it a compromise. The practical approach is to pack for warm sunshine and a change in conditions.

The sea is the catch; evenings need a layer

Air temperatures can feel inviting while the water remains cold. The sea averages 17.2°C, with a year-to-year range of 16°C to 18°C, so do not mistake a warm afternoon for comfortable swimming conditions. May is better suited to sitting by the sea than relying on long, relaxed swims. A wetsuit is worth considering if time in the water matters to you. For evenings, bring a jumper or light jacket alongside your daytime clothes. The coldest 10% of nights reach 11.8°C or lower, so a cool evening is a realistic possibility, not just a remote concern when packing.