Mariehamn weather in May

In May, Mariehamn sees average daytime highs of 8°C and overnight lows near 6°C, with 33 mm of precipitation across 6.6 wet days and about 16.8 hours of daylight. It is the 6th-warmest and 9th-wettest month of the year here.

Highs climb over the month, from about 6°C in the first days to 10°C by the end. The sky is clear or mostly clear about 41% of the time in May, and the air most often feels dry.

Daylight stretches from about 15 h 36 min at the start of May to 17 h 48 min by month's end. Set against the rest of the year, May is Mariehamn's 2nd-clearest and 10th-windiest month. For the whole year in context, see Mariehamn's year-round climate.

Daytime high: 8°; 6th warmest
Overnight low: 6°; 7th coldest
Precipitation: 33 mm; 6.6 wet days
Daylight: 16 h 48 min; 4:12 AM – 9:01 PM
Cloud cover: 51%; 2nd clearest
Wind: 20 km/h; 10th windiest
Solar energy: 5.83 kWh/m²
Travel score: 1.6; out of 10

← April Mariehamn 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 6°C in the first days to 10°C by the end.

A typical May day in Mariehamn reaches about 8°C in the afternoon and slips back to 6°C overnight — a 2°C spread between the day's warmth and the night's chill. On most days the high lands between 6°C and 11°C. Set against its neighbours, May runs about 4°C warmer than April and about 5°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)	6	6	6	6	6	7	7	7	7	7	7	7	8	8	8	8	8	8	9	9	9	9	9	9	10	10	10	10	10	10	11
Avg low (°C)	4	4	4	5	5	5	5	5	5	5	6	6	6	6	6	6	6	7	7	7	7	7	7	8	8	8	8	8	8	9	9

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

How May really feels in Mariehamn

Once humidity and wind are folded in, May averages 0 days that feel above 32°C and 2 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.

Mariehamn weather by month

How May compares with the rest of the year at a glance. May is the 6th-warmest and 9th-wettest month here — the current month is highlighted below.

Month	High / Low (°C)	Rainfall (mm)	Wet days	Snow days	Daylight (hours)	Travel score
Jan	2° / -1°	43	10.5	8	6.4	0.0
Feb	0° / -2°	29	7.7	6.5	8.6	0.0
Mar	1° / -1°	27	7.1	5.1	11.3	0.0
Apr	4° / 2°	29	6.9	1.7	14.2	0.0
May	8° / 6°	33	6.6	0.2	16.8	1.6
Jun	13° / 11°	49	7.5	0	18.4	3.8
Jul	17° / 15°	48	7.6	0	17.7	5.9
Aug	18° / 16°	55	10.2	0	15.4	5.8
Sep	14° / 13°	54	9.2	0	12.6	4.1
Oct	9° / 8°	62	11.8	0.4	9.8	1.9
Nov	6° / 4°	60	13	2.9	7.1	0.4
Dec	3° / 1°	56	13	6.1	5.6	0.0

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 41% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 16% of May, with mostly cloudy or overcast conditions the remaining 43%.

	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 (%)	54	55	55	55	56	57	57	58	58	58	59	59	59	59	59	58	57	57	57	56	56	56	56	56	56	56	56	57	58	58	58
Cloudier (%)	46	45	45	45	44	43	43	42	42	42	41	41	41	41	41	42	43	43	43	44	44	44	44	44	44	44	44	43	42	42	42

	Clearer (%)	Cloudier (%)
1	54	46
2	55	45
3	55	45
4	55	45
5	56	44
6	57	43
7	57	43
8	58	42
9	58	42
10	58	42
11	59	41
12	59	41
13	59	41
14	59	41
15	59	41
16	58	42
17	57	43
18	57	43
19	57	43
20	56	44
21	56	44
22	56	44
23	56	44
24	56	44
25	56	44
26	56	44
27	56	44
28	57	43
29	58	42
30	58	42
31	58	42

Chance of precipitation in May

Any precipitationSnow

Mariehamn gets around 33 mm of rain and snow over 6.6 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 21% and peaks near 23% on the wettest days, and about 0 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 (%)	23	23	23	23	23	22	22	22	21	21	20	20	20	20	19	19	19	20	20	20	20	21	21	21	21	21	21	21	21	21	21
Snow chance (%)	2	2	2	1	1	1	1	1	1	1	1	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0

	Rain chance (%)	Snow chance (%)
1	23	2
2	23	2
3	23	2
4	23	1
5	23	1
6	22	1
7	22	1
8	22	1
9	21	1
10	21	1
11	20	1
12	20	0
13	20	0
14	20	0
15	19	0
16	19	0
17	19	0
18	20	0
19	20	0
20	20	0
21	20	0
22	21	0
23	21	0
24	21	0
25	21	0
26	21	0
27	21	0
28	21	0
29	21	0
30	21	0
31	21	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 20 km/h on the calmest days to 21 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)	21	21	21	21	21	21	21	21	21	20	20	20	20	20	20	20	20	20	20	20	20	20	20	20	20	20	20	20	20	20	20
Feels	breezy	breezy	breezy	breezy	breezy	breezy	breezy	breezy	breezy	breezy	breezy	breezy	breezy	breezy	breezy	breezy	breezy	breezy	breezy	breezy	breezy	breezy	breezy	breezy	breezy	breezy	breezy	breezy	breezy	breezy	breezy

	Wind speed (km/h)	Feels
1	21	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	20	breezy
11	20	breezy
12	20	breezy
13	20	breezy
14	20	breezy
15	20	breezy
16	20	breezy
17	20	breezy
18	20	breezy
19	20	breezy
20	20	breezy
21	20	breezy
22	20	breezy
23	20	breezy
24	20	breezy
25	20	breezy
26	20	breezy
27	20	breezy
28	20	breezy
29	20	breezy
30	20	breezy
31	20	breezy

Sunrise & sunset in May

DaylightNight

Daylight runs from about 15 h 36 min at the start of May to 17 h 48 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 132 minutes over May. Sunrise moves from 4:51 AM to 3:42 AM, and sunset from 8:24 PM to 9:33 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)	15.6	15.7	15.7	15.8	15.9	16.0	16.1	16.2	16.2	16.3	16.4	16.5	16.6	16.7	16.7	16.8	16.9	17.0	17.0	17.1	17.2	17.3	17.3	17.4	17.5	17.5	17.6	17.7	17.7	17.8	17.8
Sunrise (AM)	4:51	4:48	4:45	4:42	4:40	4:37	4:34	4:32	4:29	4:27	4:24	4:22	4:19	4:17	4:14	4:12	4:10	4:07	4:05	4:03	4:01	3:59	3:57	3:55	3:53	3:51	3:49	3:47	3:46	3:44	3:42
Sunset (PM)	8:24	8:27	8:29	8:32	8:34	8:37	8:39	8:42	8:44	8:47	8:49	8:51	8:54	8:56	8:59	9:01	9:03	9:06	9:08	9:10	9:12	9:15	9:17	9:19	9:21	9:23	9:25	9:27	9:29	9:31	9:33

	Daylight (h)	Sunrise (AM)	Sunset (PM)
1	15.6	4:51	8:24
2	15.7	4:48	8:27
3	15.7	4:45	8:29
4	15.8	4:42	8:32
5	15.9	4:40	8:34
6	16.0	4:37	8:37
7	16.1	4:34	8:39
8	16.2	4:32	8:42
9	16.2	4:29	8:44
10	16.3	4:27	8:47
11	16.4	4:24	8:49
12	16.5	4:22	8:51
13	16.6	4:19	8:54
14	16.7	4:17	8:56
15	16.7	4:14	8:59
16	16.8	4:12	9:01
17	16.9	4:10	9:03
18	17.0	4:07	9:06
19	17.0	4:05	9:08
20	17.1	4:03	9:10
21	17.2	4:01	9:12
22	17.3	3:59	9:15
23	17.3	3:57	9:17
24	17.4	3:55	9:19
25	17.5	3:53	9:21
26	17.5	3:51	9:23
27	17.6	3:49	9:25
28	17.7	3:47	9:27
29	17.7	3:46	9:29
30	17.8	3:44	9:31
31	17.8	3:42	9:33

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.83 kWh/m².

For context, solar energy here swings from a low near 0.18 kWh/m² to a high of 6.29 kWh/m² in June across the year — May's 5.83 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)	5.2	5.2	5.3	5.3	5.4	5.4	5.5	5.5	5.6	5.6	5.7	5.7	5.8	5.8	5.8	5.9	5.9	5.9	6.0	6.0	6.0	6.1	6.1	6.1	6.2	6.2	6.2	6.2	6.3	6.3	6.3
Level	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense

	Solar energy (kWh/m²)	Level
1	5.2	Bright
2	5.2	Bright
3	5.3	Bright
4	5.3	Bright
5	5.4	Bright
6	5.4	Bright
7	5.5	Bright
8	5.5	Bright
9	5.6	Bright
10	5.6	Bright
11	5.7	Bright
12	5.7	Bright
13	5.8	Bright
14	5.8	Bright
15	5.8	Bright
16	5.9	Bright
17	5.9	Bright
18	5.9	Bright
19	6.0	Bright
20	6.0	Intense
21	6.0	Intense
22	6.1	Intense
23	6.1	Intense
24	6.1	Intense
25	6.2	Intense
26	6.2	Intense
27	6.2	Intense
28	6.2	Intense
29	6.3	Intense
30	6.3	Intense
31	6.3	Intense

Planning a trip in May

Is May a good time to visit Mariehamn?

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

1.6

Sightseeing

6th-best month of the year

0.0

Beach & pool

5th-best month of the year

May is a weaker month for outdoor sightseeing in Mariehamn.

What to pack for Mariehamn in May

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

In May, Mariehamn sees daytime highs around 8°C and nights near 6°C. Pack a warm layer. Worth having: sun protection and a windbreaker. About 7 days see rain.

a warm layersun protectiona windbreaker

Sea temperature near Mariehamn in May

The nearest coast averages about 6°C in May — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea offshore is warmest in August at about 17°C and coldest in February near 1°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)	2	1	1	3	6	11	16	17	14	10	7	4
Comfort	Bracing	Bracing	Bracing	Bracing	Bracing	Bracing	Cool	Cool	Bracing	Bracing	Bracing	Bracing

	Sea temperature (°C)	Comfort
Jan	2	Bracing
Feb	1	Bracing
Mar	1	Bracing
Apr	3	Bracing
May	6	Bracing
Jun	11	Bracing
Jul	16	Cool
Aug	17	Cool
Sep	14	Bracing
Oct	10	Bracing
Nov	7	Bracing
Dec	4	Bracing

UV index in Mariehamn in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 4 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Mariehamn peaks around June 18 at about 5 (high) — a little sun protection helps at midday. It bottoms out near December 20 at about 0 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 4 months of the year.

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

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

Location & terrain

Where is Mariehamn?

Mariehamn sits at 60.1°N, 19.9°E, 11 m above sea level, in Aland Islands. The nearest listed city is Norrtälje, 78 km away.

Topography around Mariehamn

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

Within 3 km, the terrain around Mariehamn has only modest variations in elevation — a maximum elevation change of 55 m around an average of 7 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 80 m; within 80 km, only modest variations in elevation — a maximum elevation change of 130 m.

The land around Mariehamn is covered by water (44%) and trees (32%) within 3 km, water (55%) and trees (31%) within 16 km, and water (86%) within 80 km.

3 km

55 m

water 44%

16 km

80 m

water 55%

80 km

130 m

water 86%

treesgrasslandcroplandartificial surfaceswaterwetland

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

May weather nearby: Norrtälje 78 km · Åkersberga 114 km · Vallentuna 121 km · Gustavsberg 122 km · Naantali 122 km · Boo 126 km · Täby 127 km · Märsta 128 km

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Mariehamn (60.0973°, 19.9348°, elevation 11 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	6	4
2	6	4
3	6	4
4	6	5
5	6	5
6	7	5
7	7	5
8	7	5
9	7	5
10	7	5
11	7	6
12	7	6
13	8	6
14	8	6
15	8	6
16	8	6
17	8	6
18	8	7
19	9	7
20	9	7
21	9	7
22	9	7
23	9	7
24	9	8
25	10	8
26	10	8
27	10	8
28	10	8
29	10	8
30	10	9
31	11	9

	Clearer (%)	Cloudier (%)
1	54	46
2	55	45
3	55	45
4	55	45
5	56	44
6	57	43
7	57	43
8	58	42
9	58	42
10	58	42
11	59	41
12	59	41
13	59	41
14	59	41
15	59	41
16	58	42
17	57	43
18	57	43
19	57	43
20	56	44
21	56	44
22	56	44
23	56	44
24	56	44
25	56	44
26	56	44
27	56	44
28	57	43
29	58	42
30	58	42
31	58	42

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

	Clearer (%)	Cloudier (%)
1	54	46
2	55	45
3	55	45
4	55	45
5	56	44
6	57	43
7	57	43
8	58	42
9	58	42
10	58	42
11	59	41
12	59	41
13	59	41
14	59	41
15	59	41
16	58	42
17	57	43
18	57	43
19	57	43
20	56	44
21	56	44
22	56	44
23	56	44
24	56	44
25	56	44
26	56	44
27	56	44
28	57	43
29	58	42
30	58	42
31	58	42

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

	Clearer (%)	Cloudier (%)
1	54	46
2	55	45
3	55	45
4	55	45
5	56	44
6	57	43
7	57	43
8	58	42
9	58	42
10	58	42
11	59	41
12	59	41
13	59	41
14	59	41
15	59	41
16	58	42
17	57	43
18	57	43
19	57	43
20	56	44
21	56	44
22	56	44
23	56	44
24	56	44
25	56	44
26	56	44
27	56	44
28	57	43
29	58	42
30	58	42
31	58	42

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