Kotka weather in May

In May, Kotka sees average daytime highs of 13°C and overnight lows near 6°C, with 43 mm of precipitation across 9.5 wet days and about 16.9 hours of daylight. It is the 5th-warmest and 9th-wettest month of the year here.

Highs climb over the month, from about 11°C in the first days to 15°C by the end. The sky is clear or mostly clear about 31% 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 18 hours by month's end. Set against the rest of the year, May is Kotka's 1st-clearest and 11th-windiest month. For the whole year in context, see Kotka's year-round climate.

Daytime high
13°
5th warmest
Overnight low
8th coldest
Precipitation
43 mm
9.5 wet days
Daylight
16 h 54 min
3:41 AM – 8:35 PM
Cloud cover
59%
1st clearest
Wind
13 km/h
11th windiest
Solar energy
5.35 kWh/m²
Travel score
3.7
out of 10

Kotka is urban area in Kotka, Finland.

Air quality
Good
PM10 18.7 µg/m³ · 2019

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

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 11°C in the first days to 15°C by the end.

A typical May day in Kotka reaches about 13°C in the afternoon and slips back to 6°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 8°C and 19°C. Set against its neighbours, May runs about 6°C warmer than April and about 4°C cooler than June.

10°20°151015202531
Avg high (°C)Avg low (°C)
1103
2113
3114
4114
5114
6114
7124
8124
9125
10125
11125
12135
13135
14135
15136
16136
17136
18146
19146
20146
21147
22147
23147
24147
25157
26157
27158
28158
29158
30158
31158

How May really feels in Kotka

Once humidity and wind are folded in, May averages 0 days that feel above 32°C and 1 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
0
heat index over the day's high
Days feeling ≤ C
1
wind chill below the day's low

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

Kotka weather by month

How May compares with the rest of the year at a glance. May is the 5th-warmest and 9th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan-3° / -7°4710.910.96.30.0
Feb-3° / -8°429.29.28.60.0
Mar / -5°3797.211.30.0
Apr / 358.82.614.20.9
May13° / 439.50.116.93.7
Jun17° / 10°6411.1018.55.3
Jul21° / 14°5810.1017.86.4
Aug20° / 13°6611.6015.45.9
Sep15° / 5810.2012.64.2
Oct / 6411.619.71.3
Nov / -0°61125.17.10.0
Dec-0° / -4°5912.395.50.0

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 31% of the time in May, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 14% of May, with mostly cloudy or overcast conditions the remaining 55%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14357
24258
34456
44456
54456
64456
74456
84456
94555
104555
114654
124654
134555
144555
154555
164555
174555
184555
194456
204456
214456
224456
234555
244555
254456
264555
274555
284654
294654
304654
314753

Chance of precipitation in May

Any precipitationSnow

Kotka gets around 43 mm of rain and snow over 9.5 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 30% and peaks near 33% on the wettest days, and about 0 day brings snow.

0%10%20%30%40%151015202531
Rain chance (%)Snow chance (%)
1292
2292
3292
4291
5291
6291
7291
8291
9281
10280
11280
12280
13280
14280
15280
16280
17290
18290
19300
20310
21310
22320
23320
24320
25320
26330
27330
28330
29320
30320
31320

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 98% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)
11000
21000
31000
41000
51000
61000
71000
81000
91000
101000
11991
12991
13991
14991
15991
16991
17982
18982
19982
20982
21982
22982
23973
24973
25973
26973
27973
28973
29973
30964
31964

Wind in May

Winds average 13 km/h in May.

Across May, daily wind ranges from about 13 km/h on the calmest days to 13 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202531
Wind speed (km/h)Feels
113light breeze
213light breeze
313light breeze
413light breeze
513light breeze
613light breeze
713light breeze
813light breeze
913light breeze
1013light breeze
1113light breeze
1213light breeze
1313light breeze
1413light breeze
1513light breeze
1613light breeze
1713light breeze
1813light breeze
1913light breeze
2013light breeze
2113light breeze
2213light breeze
2313light breeze
2413light breeze
2513light breeze
2613light breeze
2713light breeze
2813light breeze
2913light breeze
3013light breeze
3113light breeze

Sunrise & sunset in May

DaylightNight

Daylight runs from about 15 h 36 min at the start of May to 18 hours by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 144 minutes over May. Sunrise moves from 4:21 AM to 3:11 AM, and sunset from 7:58 PM to 9:08 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
115.64:217:58
215.74:188:01
315.84:158:03
415.94:128:06
516.04:108:08
616.14:078:11
716.24:048:13
816.24:028:16
916.33:598:18
1016.43:568:21
1116.53:548:23
1216.63:518:26
1316.73:498:28
1416.73:468:31
1516.83:448:33
1616.93:418:35
1717.03:398:38
1817.13:378:40
1917.13:358:43
2017.23:328:45
2117.33:308:47
2217.43:288:49
2317.43:268:52
2417.53:248:54
2517.63:228:56
2617.63:208:58
2717.73:189:00
2817.83:169:02
2917.83:149:04
3017.93:139:06
3118.03:119:08

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.35 kWh/m².

For context, solar energy here swings from a low near 0.14 kWh/m² to a high of 5.61 kWh/m² in June across the year — May's 5.35 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
14.8Bright
24.8Bright
34.8Bright
44.9Bright
55.0Bright
65.0Bright
75.0Bright
85.1Bright
95.1Bright
105.2Bright
115.2Bright
125.3Bright
135.3Bright
145.3Bright
155.4Bright
165.4Bright
175.4Bright
185.4Bright
195.5Bright
205.5Bright
215.5Bright
225.5Bright
235.6Bright
245.6Bright
255.6Bright
265.6Bright
275.6Bright
285.7Bright
295.7Bright
305.7Bright
315.7Bright
Planning a trip in May

Is May a good time to visit Kotka?

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

3.7
Sightseeing
5th-best month of the year
0.0
Beach & pool
5th-best month of the year

May is a weaker month for outdoor sightseeing in Kotka.

What to pack for Kotka in May

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

In May, Kotka sees daytime highs around 13°C and nights near 6°C. Worth packing: a warm layer, rain gear and sun protection. About 10 days see rain.

a warm layerrain gearsun protection

Sea temperature near Kotka 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 0°C.

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

0°10°20°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshing
Sea temperature (°C)Comfort
Jan1Bracing
Feb0Bracing
Mar0Bracing
Apr2Bracing
May6Bracing
Jun12Bracing
Jul17Cool
Aug17Cool
Sep14Bracing
Oct10Bracing
Nov7Bracing
Dec4Bracing

UV index in Kotka 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 Kotka peaks around June 20 at about 5 (high) — 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 4 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighModerateLowJun 20UV 5Dec 19UV 0
UV index (midday)Level
Jan0Low
Feb1Low
Mar2Low
Apr3Moderate
May4Moderate
Jun5High
Jul5Moderate
Aug4Moderate
Sep2Moderate
Oct1Low
Nov0Low
Dec0Low
Location & terrain

Where is Kotka?

Kotka sits at 60.5°N, 26.9°E, 1 m above sea level, in Finland. The nearest listed city is Karhula, 6.0 km away.

OrimattilaLahtiMäntsälä

Topography around Kotka

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

Within 3 km, the terrain around Kotka has only modest variations in elevation — a maximum elevation change of 32 m around an average of 4 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 87 m; within 80 km, only modest variations in elevation — a maximum elevation change of 177 m.

The land around Kotka is covered by water (59%) and artificial surfaces (20%) within 3 km, water (54%) and trees (34%) within 16 km, and water (51%) and trees (40%) within 80 km.

3 km
32 m
16 km
87 m
80 km
177 m
treesgrasslandcroplandartificial surfacesbare terrainwaterwetland
May weather nearby: Karhula 6.0 km · Hamina 18 km · Anjala 25 km · Kouvola 46 km · Porvoo 71 km · Orimattila 76 km · Lahti 90 km · Mäntsälä 91 km

Finland travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type C / F
230 V · 50 Hz
Prices
≈ 85% of US
price level, 2025
GDP per capita
$56,149
2025
Happiness
7.8 / 10
World Happiness, 2025
Safe drinking water
100%
of population, 2024
Homicide rate
1
per 100k, 2023
Road deaths
3.9
per 100k/yr, 2019
Income group
High
World Bank
English
Very high
EF EPI 603
Religion
Lutheran 67%none 31%other 2%Greek Orthodox 1%

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 Kotka (60.4664°, 26.9458°, elevation 1 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).