Viterbo weather in May

In May, Viterbo sees average daytime highs of 22°C and overnight lows near 12°C, with 63 mm of rain across 9.4 wet days and about 14.4 hours of daylight. It is the 5th-warmest and 8th-wettest month of the year here.

Highs climb over the month, from about 20°C in the first days to 24°C by the end. The sky is clear or mostly clear about 40% of the time in May, and the air most often feels dry.

Daylight stretches from about 13 h 48 min at the start of May to 14 h 48 min by month's end. Set against the rest of the year, May is Viterbo's 5th-clearest and 9th-windiest month. For the whole year in context, see Viterbo's year-round climate.

Daytime high
22°
5th warmest
Overnight low
12°
8th coldest
Rainfall
63 mm
9.4 wet days
Daylight
14 h 24 min
4:56 AM – 7:20 PM
Cloud cover
49%
5th clearest
Wind
9 km/h
9th windiest
Solar energy
6.28 kWh/m²
Travel score
6.9
out of 10
Air quality
Moderate
PM2.5 11.3 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 20°C in the first days to 24°C by the end.

A typical May day in Viterbo reaches about 22°C in the afternoon and slips back to 12°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 17°C and 26°C. Set against its neighbours, May runs about 5°C warmer than April and about 5°C cooler than June.

10°15°20°25°30°151015202531
Avg high (°C)Avg low (°C)
12011
22011
32011
42011
52011
62011
72011
82111
92112
102112
112112
122112
132112
142112
152212
162212
172212
182213
192213
202213
212213
222313
232313
242313
252313
262314
272314
282414
292414
302414
312414

How May really feels in Viterbo

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.

Viterbo 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
Jan10° / 618.20.59.32.2
Feb11° / 688.70.810.32.8
Mar14° / 749.20.511.64.3
Apr17° / 7611.10.113.15.5
May22° / 12°639.4014.46.9
Jun26° / 16°4670157.4
Jul30° / 19°284.8014.86.4
Aug30° / 19°336013.76.1
Sep25° / 16°849.1012.37.1
Oct20° / 12°11410.6010.86.4
Nov14° / 12712.10.19.64.1
Dec11° / 8610.10.492.5

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 40% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 20% of May, with mostly cloudy or overcast conditions the remaining 39%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15248
25347
35446
45446
55545
65644
75743
85743
95743
105743
115842
125941
135941
145941
156040
166139
176139
186238
196238
206337
216436
226436
236634
246634
256634
266634
276634
286733
296733
306733
316634

Chance of precipitation in May

Any precipitation

Viterbo gets around 63 mm of rain 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 rain averages around 31% 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 (%)
140
239
339
438
538
637
736
835
934
1034
1133
1232
1332
1431
1531
1630
1730
1829
1929
2028
2128
2227
2327
2427
2526
2626
2726
2826
2926
3026
3126

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 70% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)
189110
288120
386140
485150
583170
681190
780200
879210
977230
1075241
1175241
1274251
1373261
1473261
1572271
1671281
1771281
1869292
1968302
2068302
2166313
2265323
2364324
2463334
2561345
2659356
2757376
2854388
2952399
30494010
31474112

Wind in May

Winds average 9 km/h in May.

Across May, daily wind ranges from about 8 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
228calm
238calm
248calm
258calm
268calm
278calm
288calm
298calm
308calm
318calm

Sunrise & sunset in May

DaylightNight

Daylight runs from about 13 h 48 min at the start of May to 14 h 48 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 5:14 AM to 4:44 AM, and sunset from 7:03 PM to 7:34 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.85:147:03
213.95:137:05
313.95:117:06
413.95:107:07
514.05:097:08
614.05:077:09
714.15:067:10
814.15:057:11
914.15:047:12
1014.25:027:14
1114.25:017:15
1214.35:007:16
1314.34:597:17
1414.34:587:18
1514.44:577:19
1614.44:567:20
1714.44:557:21
1814.54:547:22
1914.54:537:23
2014.54:527:24
2114.64:517:25
2214.64:507:26
2314.64:497:27
2414.74:487:28
2514.74:487:29
2614.74:477:30
2714.74:467:31
2814.84:457:32
2914.84:457:33
3014.84:447:33
3114.84:447:34

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 6.28 kWh/m².

For context, solar energy here swings from a low near 1.57 kWh/m² to a high of 7.06 kWh/m² in July across the year — May's 6.28 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.7Bright
25.8Bright
35.8Bright
45.8Bright
55.9Bright
65.9Bright
76.0Bright
86.0Bright
96.0Intense
106.1Intense
116.1Intense
126.1Intense
136.2Intense
146.2Intense
156.2Intense
166.3Intense
176.3Intense
186.3Intense
196.3Intense
206.4Intense
216.4Intense
226.4Intense
236.5Intense
246.5Intense
256.5Intense
266.5Intense
276.6Intense
286.6Intense
296.6Intense
306.6Intense
316.6Intense
Planning a trip in May

Is May a good time to visit Viterbo?

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

6.9
Sightseeing
3rd-best month of the year
4.6
Beach & pool
5th-best month of the year

May is a reasonable time to visit Viterbo for sightseeing.

What to pack for Viterbo in May

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

In May, Viterbo sees daytime highs around 22°C and nights near 12°C. Pack sun protection. Worth having: rain gear. About 9 days see rain.

sun protectionrain gear

Sea temperature near Viterbo in May

The nearest coast averages about 18°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 40 km away) is warmest in August at about 25°C and coldest in February near 14°C.

It's comfortable for a long swim from Jun 2 to Oct 31 — about 5 months when the water holds above 20°C.

15°20°25°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swim
Sea temperature (°C)Comfort
Jan15Bracing
Feb14Bracing
Mar14Bracing
Apr15Cool
May18Cool
Jun22Refreshing
Jul24Warm
Aug25Warm
Sep23Refreshing
Oct21Refreshing
Nov19Cool
Dec16Cool

UV index in Viterbo 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 Viterbo peaks around July 14 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 23 at about 1 (low).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighModerateLowJul 14UV 9Dec 23UV 1
UV index (midday)Level
Jan1Low
Feb3Moderate
Mar5Moderate
Apr5Moderate
May7High
Jun9Very high
Jul9Very high
Aug8Very high
Sep5High
Oct3Moderate
Nov2Moderate
Dec1Low
Location & terrain

Where is Viterbo?

Viterbo sits at 42.4°N, 12.1°E, 326 m above sea level, in Italy. The nearest listed city is Civitavecchia, 44 km away.

Topography around Viterbo

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

Within 3 km, the terrain around Viterbo has significant variations in elevation — a maximum elevation change of 280 m around an average of 352 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 1,009 m; within 80 km, very significant variations in elevation — a maximum elevation change of 2,182 m.

The land around Viterbo is covered by trees (51%) and artificial surfaces (24%) within 3 km, trees (57%) and cropland (27%) within 16 km, and trees (47%) and cropland (20%) within 80 km.

3 km
280 m
16 km
1,009 m
80 km
2,182 m
treesshrubsgrasslandcroplandartificial surfaceswater
May weather nearby: Civitavecchia 44 km · Terni 47 km · Todi 47 km · Cerveteri 48 km · Ladispoli 52 km · Monterotondo 59 km · Mentana 62 km · Rieti 62 km

Italy travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type C / F / L
230 V · 50 Hz
Prices
≈ 69% of US
price level, 2025
GDP per capita
$43,309
2025
Happiness
6.6 / 10
World Happiness, 2025
Safe drinking water
97%
of population, 2024
Homicide rate
0.6
per 100k, 2023
Road deaths
5.3
per 100k/yr, 2019
Income group
High
World Bank
English
Moderate
EF EPI 513
Religion
Christian 81%unaffiliated 13%Muslim 5%other 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 Viterbo (42.4194°, 12.1056°, elevation 326 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).