Porvoo weather in May

In May, Porvoo sees average daytime highs of 15°C and overnight lows near 5°C, with 45 mm of precipitation across 9.4 wet days and about 16.8 hours of daylight. It is the 4th-warmest and 8th-wettest month of the year here.

Highs climb over the month, from about 13°C in the first days to 18°C by the end. The sky is clear or mostly clear about 27% 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 54 min by month's end. Set against the rest of the year, May is Porvoo's 1st-clearest and 9th-windiest month. For the whole year in context, see Porvoo's year-round climate.

Daytime high
15°
4th warmest
Overnight low
8th coldest
Precipitation
45 mm
9.4 wet days
Daylight
16 h 54 min
3:47 AM – 8:40 PM
Cloud cover
60%
1st clearest
Wind
11 km/h
9th windiest
Solar energy
5.36 kWh/m²
Travel score
4.8
out of 10

Porvoo is urban area in Porvoo, Finland.

Air quality
Good
PM10 16.6 µg/m³ · 2016

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 13°C in the first days to 18°C by the end.

A typical May day in Porvoo reaches about 15°C in the afternoon and slips back to 5°C overnight — a 10°C spread between the day's warmth and the night's chill. On most days the high lands between 10°C and 22°C. Set against its neighbours, May runs about 7°C warmer than April and about 4°C cooler than June.

10°20°151015202531
Avg high (°C)Avg low (°C)
1133
2133
3133
4133
5144
6144
7144
8144
9144
10154
11154
12155
13155
14155
15155
16155
17165
18166
19166
20166
21166
22166
23177
24177
25177
26177
27177
28178
29188
30188
31188

How May really feels in Porvoo

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
0
heat index over the day's high
Days feeling ≤ C
2
wind chill below the day's low

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

Porvoo weather by month

How May compares with the rest of the year at a glance. May is the 4th-warmest and 8th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan-2° / -7°4510.710.56.30.0
Feb-2° / -8°3998.98.60.0
Mar / -5°368.57.411.30.0
Apr / 368.82.314.21.7
May15° / 459.40.116.84.8
Jun19° / 10°7111.9018.55.8
Jul22° / 13°6811.2017.86.4
Aug21° / 12°6511.7015.46.1
Sep15° / 519.9012.64.5
Oct / 5510.40.89.71.4
Nov / -1°5410.94.77.10.0
Dec-0° / -4°5311.79.35.50.0

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 27% of the time in May, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 17% of May, with mostly cloudy or overcast conditions the remaining 56%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14258
24258
34357
44258
54258
64258
74357
84357
94357
104555
114654
124654
134654
144555
154555
164555
174456
184456
194456
204456
214357
224456
234456
244357
254456
264456
274456
284456
294456
304456
314654

Chance of precipitation in May

Any precipitationSnow

Porvoo gets around 45 mm of rain and snow over 9.4 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 32% on the wettest days, and about 0 day brings snow.

0%10%20%30%40%151015202531
Rain chance (%)Snow chance (%)
1303
2292
3292
4292
5292
6291
7281
8281
9281
10281
11281
12281
13281
14280
15280
16280
17280
18290
19290
20300
21300
22310
23310
24310
25320
26320
27320
28320
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 (%)Humid (%)
110000
210000
310000
410000
510000
610000
710000
810000
910000
109910
119910
129910
139910
149820
159820
169820
179820
189820
199730
209730
219730
229730
239730
249631
259631
269631
279631
289631
299541
309541
319541

Wind in May

Winds average 11 km/h in May.

Across May, daily wind ranges from about 11 km/h on the calmest days to 11 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
111calm
211calm
311calm
411calm
511calm
611calm
711calm
811calm
911calm
1011calm
1111calm
1211calm
1311calm
1411calm
1511calm
1611calm
1711calm
1811calm
1911calm
2011calm
2111calm
2211calm
2311calm
2411calm
2511calm
2611calm
2711calm
2811calm
2911calm
3011calm
3111calm

Sunrise & sunset in May

DaylightNight

Daylight runs from about 15 h 36 min at the start of May to 17 h 54 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 138 minutes over May. Sunrise moves from 4:26 AM to 3:17 AM, and sunset from 8:03 PM to 9:13 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
115.64:268:03
215.74:238:05
315.84:218:08
415.94:188:10
516.04:158:13
616.04:128:15
716.14:108:18
816.24:078:20
916.34:058:23
1016.44:028:25
1116.53:598:28
1216.63:578:30
1316.63:548:33
1416.73:528:35
1516.83:508:38
1616.93:478:40
1717.03:458:42
1817.03:428:45
1917.13:408:47
2017.23:388:49
2117.33:368:52
2217.33:348:54
2317.43:328:56
2417.53:308:58
2517.53:289:00
2617.63:269:03
2717.73:249:05
2817.73:229:07
2917.83:209:09
3017.93:199:11
3117.93:179:13

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.36 kWh/m².

For context, solar energy here swings from a low near 0.14 kWh/m² to a high of 5.57 kWh/m² in June across the year — May's 5.36 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
14.8Bright
24.8Bright
34.9Bright
44.9Bright
55.0Bright
65.0Bright
75.1Bright
85.1Bright
95.2Bright
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
235.5Bright
245.6Bright
255.6Bright
265.6Bright
275.6Bright
285.6Bright
295.7Bright
305.7Bright
315.7Bright
Planning a trip in May

Is May a good time to visit Porvoo?

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

4.8
Sightseeing
4th-best month of the year
0.6
Beach & pool
4th-best month of the year

May is a reasonable time to visit Porvoo for sightseeing.

What to pack for Porvoo in May

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

In May, Porvoo sees daytime highs around 15°C and nights near 5°C. Worth packing: a warm layer, rain gear and sun protection. About 9 days see rain.

a warm layerrain gearsun protection

Sea temperature near Porvoo 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 at the nearest coast (about 30 km away) is warmest in August at about 17°C and coldest in March near 1°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
Jan2Bracing
Feb1Bracing
Mar1Bracing
Apr2Bracing
May6Bracing
Jun12Bracing
Jul16Cool
Aug17Cool
Sep15Bracing
Oct10Bracing
Nov7Bracing
Dec4Bracing

UV index in Porvoo 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 Porvoo peaks around June 18 at about 5 (high) — a little sun protection helps at midday. It bottoms out near January 1 at about 0 (low).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateModerateLowJun 18UV 5Jan 1UV 0
UV index (midday)Level
Jan0Low
Feb1Low
Mar2Low
Apr3Moderate
May4Moderate
Jun5High
Jul5Moderate
Aug4Moderate
Sep2Moderate
Oct1Low
Nov0Low
Dec0Low
Location & terrain

Where is Porvoo?

Porvoo sits at 60.4°N, 25.7°E, 29 m above sea level, in Finland. The nearest listed city is Sibbo, 22 km away.

Topography around Porvoo

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

Within 3 km, the terrain around Porvoo has only modest variations in elevation — a maximum elevation change of 58 m around an average of 20 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 98 m; within 80 km, only modest variations in elevation — a maximum elevation change of 226 m.

The land around Porvoo is covered by trees (51%) and artificial surfaces (22%) within 3 km, trees (61%) within 16 km, and trees (43%) and water (42%) within 80 km.

3 km
58 m
16 km
98 m
80 km
226 m
treesgrasslandcroplandartificial surfaceswaterwetland
May weather nearby: Sibbo 22 km · Kerava 31 km · Järvenpää 33 km · Mäntsälä 33 km · Tuusula 35 km · Vuosaari 35 km · Mellunkylä 36 km · Vantaa 36 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 Porvoo (60.3923°, 25.6651°, elevation 29 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).