Porsgrunn weather in May

In May, Porsgrunn sees average daytime highs of 15°C and overnight lows near 6°C, with 74 mm of precipitation across 10.8 wet days and about 16.6 hours of daylight. It is the 5th-warmest and 9th-wettest month of the year here.

Highs climb over the month, from about 13°C in the first days to 17°C by the end. The sky is clear or mostly clear about 26% of the time in May, and the air most often feels dry.

Daylight stretches from about 15 h 24 min at the start of May to 17 h 36 min by month's end. Set against the rest of the year, May is Porsgrunn's 1st-clearest and 9th-windiest month. For the whole year in context, see Porsgrunn's year-round climate.

Daytime high
15°
5th warmest
Overnight low
8th coldest
Precipitation
74 mm
10.8 wet days
Daylight
16 h 36 min
3:59 AM – 8:36 PM
Cloud cover
61%
1st clearest
Wind
10 km/h
9th windiest
Solar energy
5.35 kWh/m²
Travel score
4.3
out of 10

Porsgrunn is town in Porsgrunn Municipality, Norway.

Air quality
Good
PM2.5 7.4 µg/m³ · 2019
Founded
1807

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 17°C by the end.

A typical May day in Porsgrunn reaches about 15°C in the afternoon and slips back to 6°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 10°C and 21°C. Set against its neighbours, May runs about 5°C warmer than April and about 3°C cooler than June.

10°20°151015202531
Avg high (°C)Avg low (°C)
1124
2134
3134
4134
5134
6134
7134
8145
9145
10145
11145
12145
13145
14145
15156
16156
17156
18156
19156
20156
21157
22167
23167
24167
25167
26167
27177
28178
29178
30178
31178

How May really feels in Porsgrunn

Once humidity and wind are folded in, May averages 0 days that feel above 32°C and 0 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
0
wind chill below the day's low

May sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Porsgrunn 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 / -5°9212.210.36.60.0
Feb / -5°629.38.48.80.0
Mar / -3°638.76.611.30.2
Apr10° / 599.43.514.12.1
May15° / 7410.80.616.64.3
Jun18° / 10°9412.50185.5
Jul20° / 12°9912.5017.45.9
Aug20° / 12°10613.4015.25.7
Sep15° / 10111.5012.64.4
Oct10° / 10712.51.59.81.9
Nov / 108135.37.40.1
Dec / -3°8412.285.90.0

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 26% of the time in May, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 18% of May, with mostly cloudy or overcast conditions the remaining 56%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14060
24159
34258
44258
54357
64357
74555
84555
94555
104555
114555
124456
134456
144456
154456
164456
174456
184357
194357
204357
214357
224357
234456
244456
254555
264555
274555
284654
294753
304753
314852

Chance of precipitation in May

Any precipitationSnow

Porsgrunn gets around 74 mm of rain and snow over 10.8 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 35% and peaks near 37% on the wettest days, and about 1 day brings snow.

0%10%20%30%40%50%151015202531
Rain chance (%)Snow chance (%)
1356
2356
3356
4345
5345
6345
7334
8334
9334
10333
11333
12333
13333
14342
15342
16352
17352
18362
19361
20361
21371
22371
23371
24370
25370
26370
27360
28360
29360
30360
31350

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 99% 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
111000
121000
13991
14991
15991
16991
17991
18991
19991
20991
21991
22991
23982
24982
25982
26982
27982
28982
29982
30982
31982

Wind in May

Winds average 10 km/h in May.

Across May, daily wind ranges from about 9 km/h on the calmest days to 10 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
110calm
210calm
310calm
410calm
510calm
610calm
710calm
810calm
910calm
1010calm
1110calm
1210calm
1310calm
1410calm
1510calm
1610calm
1710calm
1810calm
1910calm
2010calm
2110calm
2210calm
2310calm
2410calm
2510calm
2610calm
2710calm
2810calm
2910calm
3010calm
319calm

Sunrise & sunset in May

DaylightNight

Daylight runs from about 15 h 24 min at the start of May to 17 h 36 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 4:36 AM to 3:32 AM, and sunset from 8:01 PM to 9:06 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
115.44:368:01
215.54:338:04
315.64:318:06
415.74:288:08
515.84:268:11
615.84:238:13
715.94:218:15
816.04:188:18
916.14:168:20
1016.24:138:22
1116.24:118:25
1216.34:088:27
1316.44:068:29
1416.54:048:31
1516.54:028:34
1616.63:598:36
1716.73:578:38
1816.83:558:40
1916.83:538:42
2016.93:518:45
2117.03:498:47
2217.03:478:49
2317.13:458:51
2417.23:438:53
2517.23:418:55
2617.33:408:57
2717.33:388:59
2817.43:369:00
2917.53:359:02
3017.53:339:04
3117.63:329:06

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 0.24 kWh/m² to a high of 5.78 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
14.7Bright
24.8Bright
34.8Bright
44.9Bright
54.9Bright
65.0Bright
75.0Bright
85.1Bright
95.1Bright
105.2Bright
115.2Bright
125.2Bright
135.3Bright
145.3Bright
155.3Bright
165.3Bright
175.4Bright
185.4Bright
195.4Bright
205.5Bright
215.5Bright
225.5Bright
235.5Bright
245.6Bright
255.6Bright
265.6Bright
275.7Bright
285.7Bright
295.7Bright
305.8Bright
315.8Bright
Planning a trip in May

Is May a good time to visit Porsgrunn?

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

4.3
Sightseeing
5th-best month of the year
0.3
Beach & pool
5th-best month of the year

May is a reasonable time to visit Porsgrunn for sightseeing.

What to pack for Porsgrunn in May

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

In May, Porsgrunn sees daytime highs around 15°C and nights near 6°C. Worth packing: a warm layer, rain gear and sun protection. About 11 days see rain.

a warm layerrain gearsun protection

Sea temperature near Porsgrunn in May

The nearest coast averages about 11°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 18°C and coldest in February near 3°C.

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

0°5°10°15°20°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshing
Sea temperature (°C)Comfort
Jan5Bracing
Feb3Bracing
Mar4Bracing
Apr6Bracing
May11Bracing
Jun15Bracing
Jul17Cool
Aug18Cool
Sep15Cool
Oct12Bracing
Nov9Bracing
Dec6Bracing

UV index in Porsgrunn 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 Porsgrunn peaks around July 20 at about 5 (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 4 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateLowJul 20UV 5Dec 19UV 0
UV index (midday)Level
Jan0Low
Feb1Low
Mar2Low
Apr3Moderate
May4Moderate
Jun4Moderate
Jul5Moderate
Aug5Moderate
Sep3Moderate
Oct1Low
Nov0Low
Dec0Low
Location & terrain

Where is Porsgrunn?

Porsgrunn sits at 59.1°N, 9.7°E, 9 m above sea level, in Norway. The nearest listed city is Skien, 8.0 km away.

Topography around Porsgrunn

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

Within 3 km, the terrain around Porsgrunn has significant variations in elevation — a maximum elevation change of 254 m around an average of 48 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 548 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,422 m.

The land around Porsgrunn is covered by trees (46%) and artificial surfaces (23%) within 3 km, trees (73%) within 16 km, and trees (59%) and water (31%) within 80 km.

3 km
254 m
16 km
548 m
80 km
1,422 m
treesgrasslandcroplandartificial surfaceswater
May weather nearby: Skien 8.0 km · Larvik 24 km · Sandefjord 32 km · Tønsberg 45 km · Horten 56 km · Kongsberg 59 km · Moss 66 km · Fredrikstad 73 km

Norway travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type C / F
230 V · 50 Hz
Prices
≈ 91% of US
price level, 2025
GDP per capita
$94,594
2025
Happiness
7.2 / 10
World Happiness, 2025
Safe drinking water
99%
of population, 2024
Homicide rate
0.7
per 100k, 2023
Road deaths
2.1
per 100k/yr, 2019
Income group
High
World Bank
English
Very high
EF EPI 613
Religion
Church of Norway 68%other Christian 4%Muslim 3%Roman Catholic 3%

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 Porsgrunn (59.1405°, 9.6561°, elevation 9 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).