Keflavik weather in May

In May, Keflavik sees average daytime highs of 8°C and overnight lows near 5°C, with 79 mm of precipitation across 13.9 wet days and about 17.8 hours of daylight. It is the 5th-warmest and 10th-wettest month of the year here.

Highs climb over the month, from about 7°C in the first days to 9°C by the end. The sky is clear or mostly clear about 14% of the time in May, and the air most often feels dry.

Daylight stretches from about 16 h 18 min at the start of May to 19 h 18 min by month's end. Set against the rest of the year, May is Keflavik's 3rd-clearest and 9th-windiest month. For the whole year in context, see Keflavik's year-round climate.

Daytime high: 8°; 5th warmest
Overnight low: 5°; 8th coldest
Precipitation: 79 mm; 13.9 wet days
Daylight: 17 h 54 min; 4:30 AM – 10:23 PM
Cloud cover: 73%; 3rd clearest
Wind: 20 km/h; 9th windiest
Solar energy: 4.92 kWh/m²
Travel score: 1.2; out of 10

Keflavik is town in Iceland.

Founded: 1501

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

← April Keflavik year-round climate June →Best places to visit in May

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 7°C in the first days to 9°C by the end.

A typical May day in Keflavik reaches about 8°C in the afternoon and slips back to 5°C overnight — a 3°C spread between the day's warmth and the night's chill. On most days the high lands between 6°C and 10°C. Set against its neighbours, May runs about 2°C warmer than April and about 3°C cooler than June.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Avg high (°C)	7	7	7	7	7	7	7	7	7	8	8	8	8	8	8	8	8	8	8	8	8	9	9	9	9	9	9	9	9	9	9
Avg low (°C)	4	4	4	4	4	4	4	4	4	4	4	4	5	5	5	5	5	5	5	5	5	6	6	6	6	6	6	6	6	6	7

	Avg high (°C)	Avg low (°C)
1	7	4
2	7	4
3	7	4
4	7	4
5	7	4
6	7	4
7	7	4
8	7	4
9	7	4
10	8	4
11	8	4
12	8	4
13	8	5
14	8	5
15	8	5
16	8	5
17	8	5
18	8	5
19	8	5
20	8	5
21	8	5
22	9	6
23	9	6
24	9	6
25	9	6
26	9	6
27	9	6
28	9	6
29	9	6
30	9	6
31	9	7

How May really feels in Keflavik

Once humidity and wind are folded in, May averages 0 days that feel above 32°C and 10 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C

heat index over the day's high

Days feeling ≤ 0°C

wind chill below the day's low

The story in May is cold — wind chill drags the overnight "feels like" below the raw low.

Keflavik weather by month

How May compares with the rest of the year at a glance. May is the 5th-warmest and 10th-wettest month here — the current month is highlighted below.

Month	High / Low (°C)	Rainfall (mm)	Wet days	Snow days	Daylight (hours)	Travel score
Jan	3° / 0°	125	18.8	9.7	5	0.0
Feb	3° / -0°	123	17.4	10.4	8	0.0
Mar	4° / 0°	113	17.6	9.3	11.2	0.0
Apr	6° / 2°	91	15.4	3.4	14.6	0.3
May	8° / 5°	79	13.9	0.5	17.8	1.2
Jun	11° / 8°	67	12.8	0	20.1	2.3
Jul	12° / 10°	74	12.8	0	19.1	3.0
Aug	12° / 10°	97	14.2	0	16	2.8
Sep	10° / 7°	134	17.2	0	12.7	1.8
Oct	7° / 4°	120	15.4	1.6	9.3	0.8
Nov	5° / 2°	124	17.2	4.9	6.1	0.0
Dec	4° / 1°	129	18.6	9.1	3.9	0.0

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 14% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 15% of May, with mostly cloudy or overcast conditions the remaining 71%.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Clearer (%)	28	29	29	29	29	30	30	30	30	30	30	32	32	31	31	31	31	30	29	29	29	29	28	27	26	26	26	26	26	26	25
Cloudier (%)	72	71	71	71	71	70	70	70	70	70	70	68	68	69	69	69	69	70	71	71	71	71	72	73	74	74	74	74	74	74	75

	Clearer (%)	Cloudier (%)
1	28	72
2	29	71
3	29	71
4	29	71
5	29	71
6	30	70
7	30	70
8	30	70
9	30	70
10	30	70
11	30	70
12	32	68
13	32	68
14	31	69
15	31	69
16	31	69
17	31	69
18	30	70
19	29	71
20	29	71
21	29	71
22	29	71
23	28	72
24	27	73
25	26	74
26	26	74
27	26	74
28	26	74
29	26	74
30	26	74
31	25	75

Chance of precipitation in May

Any precipitationSnow

Keflavik gets around 79 mm of rain and snow over 13.9 wet days in May. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 45% and peaks near 48% on the wettest days, and about 1 day brings snow.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Rain chance (%)	48	48	47	47	47	46	46	45	45	44	44	43	43	43	43	43	43	43	43	44	44	44	44	45	44	44	44	44	44	44	44
Snow chance (%)	5	5	5	4	4	4	3	3	3	2	2	2	1	1	1	1	1	1	0	0	0	0	0	0	0	0	0	0	0	0	0

	Rain chance (%)	Snow chance (%)
1	48	5
2	48	5
3	47	5
4	47	4
5	47	4
6	46	4
7	46	3
8	45	3
9	45	3
10	44	2
11	44	2
12	43	2
13	43	1
14	43	1
15	43	1
16	43	1
17	43	1
18	43	1
19	43	0
20	44	0
21	44	0
22	44	0
23	44	0
24	45	0
25	44	0
26	44	0
27	44	0
28	44	0
29	44	0
30	44	0
31	44	0

Humidity in May

DryComfortableHumidMuggyOppressiveMiserable

Most of May feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, May lands in the dry band about 100% of days. It rarely turns muggy — the humid and sticky bands barely register.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Dry (%)	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100
31	100

Wind in May

Winds average 20 km/h in May.

Across May, daily wind ranges from about 19 km/h on the calmest days to 22 km/h at its breeziest. It stays fairly steady from day to day.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Wind speed (km/h)	22	21	21	21	21	21	21	21	21	21	20	20	20	20	20	20	20	20	20	20	20	20	19	19	19	19	19	19	19	19	19
Feels	breezy	breezy	breezy	breezy	breezy	breezy	breezy	breezy	breezy	breezy	breezy	breezy	breezy	breezy	breezy	breezy	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze

	Wind speed (km/h)	Feels
1	22	breezy
2	21	breezy
3	21	breezy
4	21	breezy
5	21	breezy
6	21	breezy
7	21	breezy
8	21	breezy
9	21	breezy
10	21	breezy
11	20	breezy
12	20	breezy
13	20	breezy
14	20	breezy
15	20	breezy
16	20	breezy
17	20	light breeze
18	20	light breeze
19	20	light breeze
20	20	light breeze
21	20	light breeze
22	20	light breeze
23	19	light breeze
24	19	light breeze
25	19	light breeze
26	19	light breeze
27	19	light breeze
28	19	light breeze
29	19	light breeze
30	19	light breeze
31	19	light breeze

Sunrise & sunset in May

DaylightNight

Daylight runs from about 16 h 18 min at the start of May to 19 h 18 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 180 minutes over May. Sunrise moves from 5:19 AM to 3:49 AM, and sunset from 9:36 PM to 11:06 PM.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Daylight (h)	16.3	16.4	16.5	16.6	16.7	16.8	16.9	17.0	17.1	17.2	17.3	17.5	17.6	17.7	17.8	17.9	18.0	18.1	18.2	18.3	18.4	18.5	18.6	18.7	18.8	18.9	18.9	19.0	19.1	19.2	19.3
Sunrise (AM)	5:19	5:16	5:13	5:09	5:06	5:02	4:59	4:56	4:53	4:49	4:46	4:43	4:40	4:37	4:33	4:30	4:27	4:24	4:21	4:18	4:15	4:13	4:10	4:07	4:04	4:01	3:59	3:56	3:54	3:51	3:49
Sunset (PM)	9:36	9:39	9:42	9:45	9:48	9:51	9:54	9:58	10:01	10:04	10:07	10:10	10:13	10:16	10:20	10:23	10:26	10:29	10:32	10:35	10:38	10:41	10:44	10:47	10:50	10:53	10:56	10:58	11:01	11:04	11:06

	Daylight (h)	Sunrise (AM)	Sunset (PM)
1	16.3	5:19	9:36
2	16.4	5:16	9:39
3	16.5	5:13	9:42
4	16.6	5:09	9:45
5	16.7	5:06	9:48
6	16.8	5:02	9:51
7	16.9	4:59	9:54
8	17.0	4:56	9:58
9	17.1	4:53	10:01
10	17.2	4:49	10:04
11	17.3	4:46	10:07
12	17.5	4:43	10:10
13	17.6	4:40	10:13
14	17.7	4:37	10:16
15	17.8	4:33	10:20
16	17.9	4:30	10:23
17	18.0	4:27	10:26
18	18.1	4:24	10:29
19	18.2	4:21	10:32
20	18.3	4:18	10:35
21	18.4	4:15	10:38
22	18.5	4:13	10:41
23	18.6	4:10	10:44
24	18.7	4:07	10:47
25	18.8	4:04	10:50
26	18.9	4:01	10:53
27	18.9	3:59	10:56
28	19.0	3:56	10:58
29	19.1	3:54	11:01
30	19.2	3:51	11:04
31	19.3	3:49	11:06

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 4.92 kWh/m².

For context, solar energy here swings from a low near 0.05 kWh/m² to a high of 5.38 kWh/m² in June across the year — May's 4.92 kWh/m² sits near the top of that range.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Solar energy (kWh/m²)	4.3	4.4	4.4	4.5	4.5	4.6	4.6	4.7	4.7	4.8	4.8	4.8	4.9	4.9	5.0	5.0	5.0	5.0	5.0	5.1	5.1	5.1	5.1	5.1	5.2	5.2	5.2	5.2	5.2	5.2	5.3
Level	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright

	Solar energy (kWh/m²)	Level
1	4.3	Bright
2	4.4	Bright
3	4.4	Bright
4	4.5	Bright
5	4.5	Bright
6	4.6	Bright
7	4.6	Bright
8	4.7	Bright
9	4.7	Bright
10	4.8	Bright
11	4.8	Bright
12	4.8	Bright
13	4.9	Bright
14	4.9	Bright
15	5.0	Bright
16	5.0	Bright
17	5.0	Bright
18	5.0	Bright
19	5.0	Bright
20	5.1	Bright
21	5.1	Bright
22	5.1	Bright
23	5.1	Bright
24	5.1	Bright
25	5.2	Bright
26	5.2	Bright
27	5.2	Bright
28	5.2	Bright
29	5.2	Bright
30	5.2	Bright
31	5.3	Bright

Planning a trip in May

Is May a good time to visit Keflavik?

Our two travel scores rate May for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

1.2

Sightseeing

5th-best month of the year

—

Beach & pool

never really warm enough

May is a weaker month for outdoor sightseeing in Keflavik.

What to pack for Keflavik in May

From May's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In May, Keflavik sees daytime highs around 8°C and nights near 5°C. Pack a warm layer. Worth having: a heavy coat, rain gear, sun protection and a windbreaker. About 14 days see rain.

a warm layera heavy coatrain gearsun protectiona windbreaker

Sea temperature near Keflavik in May

The nearest coast averages about 7°C in May — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 14 km away) is warmest in August at about 11°C and coldest in March near 5°C.

The water stays below 20°C all year — cool enough that most swimmers want a wetsuit.

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Sea temperature (°C)	6	5	5	6	7	9	11	11	10	8	7	6
Comfort	Bracing	Bracing	Bracing	Bracing	Bracing	Bracing	Bracing	Bracing	Bracing	Bracing	Bracing	Bracing

	Sea temperature (°C)	Comfort
Jan	6	Bracing
Feb	5	Bracing
Mar	5	Bracing
Apr	6	Bracing
May	7	Bracing
Jun	9	Bracing
Jul	11	Bracing
Aug	11	Bracing
Sep	10	Bracing
Oct	8	Bracing
Nov	7	Bracing
Dec	6	Bracing

UV index in Keflavik in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 3 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Keflavik peaks around June 21 at about 4 (moderate) — a little sun protection helps at midday. It bottoms out near December 19 at about 0 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 3 months of the year.

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
UV index (midday)	0	0	1	2	3	5	4	3	2	1	0	0
Level	Low	Low	Low	Moderate	Moderate	Moderate	Moderate	Moderate	Low	Low	Low	Low

	UV index (midday)	Level
Jan	0	Low
Feb	0	Low
Mar	1	Low
Apr	2	Moderate
May	3	Moderate
Jun	5	Moderate
Jul	4	Moderate
Aug	3	Moderate
Sep	2	Low
Oct	1	Low
Nov	0	Low
Dec	0	Low

Location & terrain

Where is Keflavik?

Keflavik sits at 64.0°N, 22.6°W, 5 m above sea level, in Iceland. The nearest listed city is Reykjanesbær, 1.0 km away.

Topography around Keflavik

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Keflavik.

Within 3 km, the terrain around Keflavik has only modest variations in elevation — a maximum elevation change of 60 m around an average of 17 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 187 m; within 80 km, large variations in elevation — a maximum elevation change of 1,065 m.

The land around Keflavik is covered by grassland (45%) and water (37%) within 3 km, water (57%) and grassland (36%) within 16 km, and water (67%) and grassland (28%) within 80 km.

3 km

60 m

grassland 45%

16 km

187 m

water 57%

80 km

1,065 m

water 67%

treesshrubsgrasslandcroplandartificial surfacesbare terrainwaterwetlandmoss and lichen

← April Keflavik year-round climate June →Best places to visit in May

May weather nearby: Reykjanesbær 1.0 km · Hafnarfjörður 31 km · Kópavogur 34 km · Reykjavik 36 km · Vik 187 km · Akureyri 282 km · Tórshavn 825 km · Isle of Lewis 1,076 km

Iceland travel facts

Travel advisory: Level 1; Exercise Normal Precautions
Power plugs: Type C / F; 230 V · 50 Hz
Prices: ≈ 118% of US; price level, 2025
GDP per capita: $98,323; 2025
Happiness: 7.5 / 10; World Happiness, 2025
Safe drinking water: 100%; of population, 2024
Homicide rate: 1.3; per 100k, 2023
Road deaths: 2; per 100k/yr, 2019
Income group: High; World Bank
Religion

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Keflavik (64.0049°, -22.5624°, elevation 5 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).

	Avg high (°C)	Avg low (°C)
1	7	4
2	7	4
3	7	4
4	7	4
5	7	4
6	7	4
7	7	4
8	7	4
9	7	4
10	8	4
11	8	4
12	8	4
13	8	5
14	8	5
15	8	5
16	8	5
17	8	5
18	8	5
19	8	5
20	8	5
21	8	5
22	9	6
23	9	6
24	9	6
25	9	6
26	9	6
27	9	6
28	9	6
29	9	6
30	9	6
31	9	7

	Clearer (%)	Cloudier (%)
1	28	72
2	29	71
3	29	71
4	29	71
5	29	71
6	30	70
7	30	70
8	30	70
9	30	70
10	30	70
11	30	70
12	32	68
13	32	68
14	31	69
15	31	69
16	31	69
17	31	69
18	30	70
19	29	71
20	29	71
21	29	71
22	29	71
23	28	72
24	27	73
25	26	74
26	26	74
27	26	74
28	26	74
29	26	74
30	26	74
31	25	75

	Rain chance (%)	Snow chance (%)
1	48	5
2	48	5
3	47	5
4	47	4
5	47	4
6	46	4
7	46	3
8	45	3
9	45	3
10	44	2
11	44	2
12	43	2
13	43	1
14	43	1
15	43	1
16	43	1
17	43	1
18	43	1
19	43	0
20	44	0
21	44	0
22	44	0
23	44	0
24	45	0
25	44	0
26	44	0
27	44	0
28	44	0
29	44	0
30	44	0
31	44	0

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100
31	100

	Avg high (°C)	Avg low (°C)
1	7	4
2	7	4
3	7	4
4	7	4
5	7	4
6	7	4
7	7	4
8	7	4
9	7	4
10	8	4
11	8	4
12	8	4
13	8	5
14	8	5
15	8	5
16	8	5
17	8	5
18	8	5
19	8	5
20	8	5
21	8	5
22	9	6
23	9	6
24	9	6
25	9	6
26	9	6
27	9	6
28	9	6
29	9	6
30	9	6
31	9	7

	Clearer (%)	Cloudier (%)
1	28	72
2	29	71
3	29	71
4	29	71
5	29	71
6	30	70
7	30	70
8	30	70
9	30	70
10	30	70
11	30	70
12	32	68
13	32	68
14	31	69
15	31	69
16	31	69
17	31	69
18	30	70
19	29	71
20	29	71
21	29	71
22	29	71
23	28	72
24	27	73
25	26	74
26	26	74
27	26	74
28	26	74
29	26	74
30	26	74
31	25	75

	Rain chance (%)	Snow chance (%)
1	48	5
2	48	5
3	47	5
4	47	4
5	47	4
6	46	4
7	46	3
8	45	3
9	45	3
10	44	2
11	44	2
12	43	2
13	43	1
14	43	1
15	43	1
16	43	1
17	43	1
18	43	1
19	43	0
20	44	0
21	44	0
22	44	0
23	44	0
24	45	0
25	44	0
26	44	0
27	44	0
28	44	0
29	44	0
30	44	0
31	44	0

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100
31	100

	Avg high (°C)	Avg low (°C)
1	7	4
2	7	4
3	7	4
4	7	4
5	7	4
6	7	4
7	7	4
8	7	4
9	7	4
10	8	4
11	8	4
12	8	4
13	8	5
14	8	5
15	8	5
16	8	5
17	8	5
18	8	5
19	8	5
20	8	5
21	8	5
22	9	6
23	9	6
24	9	6
25	9	6
26	9	6
27	9	6
28	9	6
29	9	6
30	9	6
31	9	7

	Clearer (%)	Cloudier (%)
1	28	72
2	29	71
3	29	71
4	29	71
5	29	71
6	30	70
7	30	70
8	30	70
9	30	70
10	30	70
11	30	70
12	32	68
13	32	68
14	31	69
15	31	69
16	31	69
17	31	69
18	30	70
19	29	71
20	29	71
21	29	71
22	29	71
23	28	72
24	27	73
25	26	74
26	26	74
27	26	74
28	26	74
29	26	74
30	26	74
31	25	75

	Rain chance (%)	Snow chance (%)
1	48	5
2	48	5
3	47	5
4	47	4
5	47	4
6	46	4
7	46	3
8	45	3
9	45	3
10	44	2
11	44	2
12	43	2
13	43	1
14	43	1
15	43	1
16	43	1
17	43	1
18	43	1
19	43	0
20	44	0
21	44	0
22	44	0
23	44	0
24	45	0
25	44	0
26	44	0
27	44	0
28	44	0
29	44	0
30	44	0
31	44	0

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100
31	100