Keflavík Weather in May
Thinking of visiting Keflavík in May? Expect low temperatures reaching 9°C (48°F) during the day, dropping to 5°C (41°F) at night, and note that quite a bit of rainfall is likely.
Rainfall in Keflavík in May
Historically, the month has about 16 days of rain, averaging 87 mm (3.4 in) in total. Expect a fairly normal spread of rainfall this month, with no particular pattern of very heavy or very persistent showers.
Temperature in Keflavík in May
May in Keflavík brings low temperatures, with highs of 9°C (48°F) and nights around 5°C (41°F). Cold conditions persist throughout the day, so warm clothing is important from the moment you head outside. With lows around 5°C (41°F), nights are cold. The upside is that cool, crisp nights are often the best for a deep sleep.
Sunshine in Keflavík in May
With approximately 201 hours of sunshine, the days are filled with clear skies. Despite it being a cool month, it makes for pleasant days outside.May in Keflavík can still be great, but if you prefer pleasant temperatures along with dry and sunny conditions, our weather planner can help you explore other options in the world.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Iceland, check out our Keflavík's climate page.
Keflavík Temperature in May
Min Temperature
5°C (41°F)
Max Temperature
9°C (48°F)
Chance of Rain
52%
Precipitation
87 mm (3.4 in)
Rainy days
16 days
Humidity
76% *
Sunshine
201 hours *
Percentage Sunshine
35% *
Daily Historical Temperatures
50-year average (1976-2025)
Based on our historical records, temperatures in Keflavík typically rise from around 7°C (45°F) at the start of May to approximately 10°C (50°F) by the end. Nights are cold, with lows typically ranging from 2°C (36°F) to 6°C (43°F).
Average temperatures in May
Daily Historical Precipitation
50-year average (1976-2025)
Average daily rainfall for each day of the month based on long-term records.
Average precipitation in May
Historical weather for Keflavík in May
Browse day-by-day weather records for Keflavík spanning 51 years. Select any month and year to see actual temperatures, rainfall, and conditions recorded on each day.
Keflavík historical weather extremes in May
Based on weather observations in Keflavík between 1976 and 2026, these are the recorded extremes during May.
- The hottest May day on record in Keflavík reached 21°C (70°F) (May 18, 2025).
- The coldest May day was on May 3, 1982, with a maximum of -2°C (28°F).
- The coldest night in May in Keflavík was on May 5, 1982, with a minimum of -6°C (21°F).
- The heaviest May precipitation occurred on May 24, 2024, when 51 mm (2 in) of precipitation fell.
Best Places in Iceland in May
Find out more about the weather in Iceland and which places have the best travel conditions in this month. See all of Iceland in May →
perfect weather
pleasant
tolerable
unpleasant
poor
What to Wear in Keflavík in May
We recommend to layer up for chilly conditions in Keflavík in May. You could start with thermal underwear or a good base layer to keep your core warm on the cooler days this month. Maybe also add a sweater or fleece, and top it off with a windproof jacket. High rain levels are expected, so pack waterproof gear and an umbrella or poncho. Don't forget sun protection, sunglasses, sunscreen, and a hat. These are all good ideas with this much sunshine.What To Do in Keflavík in May
We rated the following activities from 1 (least suitable) to 10 (best) to do.
Check the conditions for any month of the year.
For a detailed overview over the year and the best time to visit Iceland, check out our Keflavík's climate page.
Temperature Rainfall Sunshine Humidity
See the full Keflavík climate overview or explore weather in Iceland.
