Viseu weather in May

In May, Viseu sees average daytime highs of 20°C and overnight lows near 10°C, with 98 mm of rain across 11.6 wet days and about 14.2 hours of daylight. It is the 5th-warmest and 8th-wettest month of the year here.

Highs climb over the month, from about 18°C in the first days to 21°C by the end. The sky is clear or mostly clear about 30% of the time in May, and the air most often feels dry.

Daylight stretches from about 13 h 42 min at the start of May to 14 h 42 min by month's end. Set against the rest of the year, May is Viseu's 6th-clearest and 8th-windiest month. For the whole year in context, see Viseu's year-round climate.

Daytime high
20°
5th warmest
Overnight low
10°
7th coldest
Rainfall
98 mm
11.6 wet days
Daylight
14 h 18 min
5:20 AM – 7:36 PM
Cloud cover
56%
6th clearest
Wind
9 km/h
8th windiest
Solar energy
6.11 kWh/m²
Travel score
6.1
out of 10

Viseu is city seat of Viseu municipality.

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 18°C in the first days to 21°C by the end.

A typical May day in Viseu reaches about 20°C in the afternoon and slips back to 10°C overnight — a 10°C spread between the day's warmth and the night's chill. On most days the high lands between 14°C and 26°C. Set against its neighbours, May runs about 3°C warmer than April and about 4°C cooler than June.

10°20°30°151015202531
Avg high (°C)Avg low (°C)
1188
2188
3189
4189
5189
6189
7189
8189
9199
10199
11199
12199
131910
141910
151910
162010
172010
182010
192010
202010
212011
222011
232111
242111
252111
262111
272111
282111
292111
302112
312212

Viseu weather by month

How May compares with the rest of the year at a glance. May is the 5th-warmest and 8th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan11° / 15211.60.59.42.5
Feb12° / 1029.30.310.43.3
Mar15° / 11510.6011.74.5
Apr17° / 11812.8013.14.9
May20° / 10°9811.6014.26.1
Jun23° / 13°406.2014.97.7
Jul27° / 15°193.7014.68.2
Aug27° / 15°264.6013.68.0
Sep24° / 13°667.1012.37.6
Oct19° / 10°16812.2010.95.7
Nov14° / 15012.70.19.73.7
Dec11° / 16011.60.19.12.7

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 30% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 17% of May, with mostly cloudy or overcast conditions the remaining 53%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14159
24159
34159
44159
54159
64159
74159
84159
94159
104258
114258
124258
134357
144555
154555
164753
174753
184852
194852
205050
215050
225149
235248
245248
255248
265248
275347
285347
295347
305347
315347

Chance of precipitation in May

Any precipitation

Viseu gets around 98 mm of rain over 11.6 wet days in May. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 37% and peaks near 40% on the wettest days. The odds ease toward the end of the month.

0%10%20%30%40%50%151015202531
Rain chance (%)
139
239
339
440
540
640
740
840
940
1040
1140
1240
1340
1439
1539
1639
1738
1838
1938
2037
2137
2236
2336
2435
2535
2634
2733
2833
2932
3032
3131

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 87% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)
19640
29640
39550
49460
59460
69370
79280
89280
99190
1090100
1190100
1289110
1389110
1488120
1588120
1687130
1787130
1886140
1985141
2085141
2184151
2284151
2383152
2482162
2582162
2681172
2781172
2880182
2980182
3079192
3178202

Wind in May

Winds average 9 km/h in May.

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

051015151015202531
Wind speed (km/h)Feels
19calm
29calm
39calm
49calm
59calm
69calm
79calm
89calm
99calm
109calm
119calm
129calm
139calm
149calm
159calm
169calm
179calm
189calm
199calm
209calm
219calm
229calm
239calm
249calm
259calm
269calm
279calm
289calm
299calm
309calm
319calm

Sunrise & sunset in May

DaylightNight

Daylight runs from about 13 h 42 min at the start of May to 14 h 42 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 60 minutes over May. Sunrise moves from 5:37 AM to 5:09 AM, and sunset from 7:20 PM to 7:49 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.75:377:20
213.85:367:21
313.85:357:22
413.85:347:23
513.95:327:24
613.95:317:25
713.95:307:26
814.05:297:28
914.05:287:29
1014.15:267:30
1114.15:257:31
1214.15:247:32
1314.25:237:33
1414.25:227:34
1514.25:217:35
1614.35:207:36
1714.35:197:37
1814.35:187:38
1914.45:177:38
2014.45:177:39
2114.45:167:40
2214.45:157:41
2314.55:147:42
2414.55:137:43
2514.55:137:44
2614.55:127:45
2714.65:117:46
2814.65:117:47
2914.65:107:47
3014.65:107:48
3114.75:097:49

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 6.11 kWh/m².

For context, solar energy here swings from a low near 1.66 kWh/m² to a high of 7.25 kWh/m² in July across the year — May's 6.11 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
15.6Bright
25.7Bright
35.7Bright
45.7Bright
55.8Bright
65.8Bright
75.8Bright
85.8Bright
95.9Bright
105.9Bright
115.9Bright
126.0Bright
136.0Intense
146.0Intense
156.1Intense
166.1Intense
176.2Intense
186.2Intense
196.2Intense
206.3Intense
216.3Intense
226.3Intense
236.3Intense
246.4Intense
256.4Intense
266.4Intense
276.4Intense
286.5Intense
296.5Intense
306.5Intense
316.5Intense
Planning a trip in May

Hazard calendar for Viseu

In seasonPeak

In May, Viseu sits inside its rainy season season. The full year is below, with each hazard's peak months called out.

Viseu's rainy season runs October–May, when most of the year's rain falls.

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

Is May a good time to visit Viseu?

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

6.1
Sightseeing
5th-best month of the year
3.0
Beach & pool
5th-best month of the year

May is a reasonable time to visit Viseu for sightseeing.

What to pack for Viseu in May

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

In May, Viseu sees daytime highs around 20°C and nights near 10°C. Pack sun protection. Worth having: rain gear. About 12 days see rain.

sun protectionrain gear

UV index in Viseu in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 7 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Viseu peaks around July 13 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 20 at about 2 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highHighModerateLowJul 13UV 9Dec 20UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5High
Apr7High
May7High
Jun9Very high
Jul9Very high
Aug9Very high
Sep6High
Oct5Moderate
Nov2Moderate
Dec2Low

Air quality in Viseu in May

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where May falls, not just the annual average.

Air quality in Viseu is worst in October — around 29 µg/m³ PM2.5 (moderate), about 3.9× the cleanest month (November, 7 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodModerateModerateGoodOct 1228 µg/m³Nov 237 µg/m³
PM2.5 (µg/m³)Level
Jan9Good
Feb10Good
Mar13Moderate
Apr11Good
May8Good
Jun21Moderate
Jul9Good
Aug24Moderate
Sep23Moderate
Oct29Moderate
Nov7Good
Dec7Good
Location & terrain

Where is Viseu?

Viseu sits at 40.7°N, 7.9°W, 469 m above sea level, in Portugal. The nearest listed city is Arouca, 41 km away.

Topography around Viseu

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

Within 3 km, the terrain around Viseu has only modest variations in elevation — a maximum elevation change of 165 m around an average of 466 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 814 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,993 m.

The land around Viseu is covered by trees (45%) and artificial surfaces (35%) within 3 km, trees (56%) and grassland (36%) within 16 km, and trees (48%) and grassland (41%) within 80 km.

3 km
165 m
16 km
814 m
80 km
1,993 m
treesshrubsgrasslandcroplandartificial surfaceswater
May weather nearby: Arouca 41 km · Covilhã 54 km · São João da Madeira 56 km · Guarda 56 km · Baião 57 km · Sequeira 59 km · Feira 61 km · Vilar 61 km

Portugal travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type C / E / F
230 V · 50 Hz
Prices
≈ 60% of US
price level, 2025
GDP per capita
$32,082
2025
Happiness
6.0 / 10
World Happiness, 2025
Safe drinking water
95%
of population, 2024
Homicide rate
0.7
per 100k, 2022
Road deaths
8.2
per 100k/yr, 2019
Income group
High
World Bank
English
Very high
EF EPI 612
Religion
Catholic 68%not applicable 13%no religion 12%no response 2%

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 Viseu (40.6617°, -7.909°, elevation 469 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. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).