Spa weather in May

In May, Spa sees average daytime highs of 17°C and overnight lows near 8°C, with 74 mm of rain across 14 wet days and about 15.2 hours of daylight. It is the 5th-warmest and 10th-wettest month of the year here.

Highs climb over the month, from about 15°C in the first days to 18°C by the end. The sky is clear or mostly clear about 15% of the time in May, and the air most often feels dry.

Daylight stretches from about 14 h 24 min at the start of May to 15 h 48 min by month's end. Set against the rest of the year, May is Spa's 6th-clearest and 9th-windiest month. For the whole year in context, see Spa's year-round climate.

Daytime high
17°
5th warmest
Overnight low
8th coldest
Rainfall
74 mm
14 wet days
Daylight
15 h 12 min
4:56 AM – 8:10 PM
Cloud cover
70%
6th clearest
Wind
13 km/h
9th windiest
Solar energy
4.97 kWh/m²
Travel score
4.7
out of 10

Spa is town in Spa municipality, Belgium.

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 15°C in the first days to 18°C by the end.

A typical May day in Spa reaches about 17°C in the afternoon and slips back to 8°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between 11°C and 23°C. Set against its neighbours, May runs about 4°C warmer than April and about 3°C cooler than June.

10°15°20°25°151015202531
Avg high (°C)Avg low (°C)
1157
2157
3157
4157
5167
6167
7167
8168
9168
10168
11168
12168
13168
14168
15168
16178
17178
18178
19178
20179
21179
22179
23179
24189
25189
26189
27189
281810
291810
301810
311810

How May really feels in Spa

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.

Spa weather by month

How May compares with the rest of the year at a glance. May is the 5th-warmest and 10th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / 9814.94.58.30.0
Feb / 8713.75.49.70.1
Mar / 8715.13.611.51.5
Apr13° / 6312.60.613.53.3
May17° / 7414015.24.7
Jun20° / 11°8413.7016.15.5
Jul22° / 13°8914.6015.85.9
Aug21° / 13°8913.6014.35.9
Sep18° / 10°7411.9012.45.2
Oct13° / 7613.2010.43.4
Nov / 8214.41.78.71.2
Dec / 10315.84.87.90.0

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 15% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 14% of May, with mostly cloudy or overcast conditions the remaining 71%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
12971
22971
32971
42971
53070
63070
73070
83070
93070
103070
113070
122872
132872
142872
152872
162872
172872
182872
192872
202872
212872
222872
232872
242872
252971
262971
272971
282971
293070
303070
313070

Chance of precipitation in May

Any precipitation

Spa gets around 74 mm of rain over 14 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 46% and peaks near 47% on the wettest days.

0%20%40%60%151015202531
Rain chance (%)
147
247
347
446
546
645
745
845
945
1045
1145
1245
1345
1445
1545
1645
1745
1845
1945
2045
2146
2246
2346
2446
2546
2646
2746
2846
2946
3046
3147

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 92% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)
19910
29910
39910
49910
59820
69820
79820
89730
99730
109730
119730
129640
139640
149640
159640
169550
179550
189460
199361
209271
219181
229181
239091
2489101
2587112
2685132
2784142
2883152
2981163
3080173
3178184

Wind in May

Winds average 13 km/h in May.

Across May, daily wind ranges from about 12 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
2912light breeze
3012light breeze
3112light breeze

Sunrise & sunset in May

DaylightNight

Daylight runs from about 14 h 24 min at the start of May to 15 h 48 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 84 minutes over May. Sunrise moves from 5:21 AM to 4:39 AM, and sunset from 7:47 PM to 8:29 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
114.45:217:47
214.55:197:48
314.65:177:50
414.65:157:52
514.75:137:53
614.75:127:55
714.85:107:56
814.85:087:58
914.95:077:59
1014.95:058:01
1115.05:038:02
1215.05:028:04
1315.15:008:05
1415.14:598:07
1515.24:578:08
1615.24:568:10
1715.34:548:11
1815.34:538:13
1915.44:528:14
2015.44:508:15
2115.54:498:17
2215.54:488:18
2315.54:478:20
2415.64:458:21
2515.64:448:22
2615.74:438:23
2715.74:428:25
2815.74:418:26
2915.84:408:27
3015.84:398:28
3115.84:398:29

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 4.97 kWh/m².

For context, solar energy here swings from a low near 0.64 kWh/m² to a high of 5.32 kWh/m² in June across the year — May's 4.97 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
14.7Bright
24.7Bright
34.7Bright
44.7Bright
54.8Bright
64.8Bright
74.8Bright
84.8Bright
94.8Bright
104.8Bright
114.8Bright
124.9Bright
134.9Bright
144.9Bright
154.9Bright
164.9Bright
175.0Bright
185.0Bright
195.0Bright
205.0Bright
215.0Bright
225.1Bright
235.1Bright
245.1Bright
255.1Bright
265.2Bright
275.2Bright
285.2Bright
295.2Bright
305.2Bright
315.2Bright
Planning a trip in May

Is May a good time to visit Spa?

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

4.7
Sightseeing
5th-best month of the year
1.0
Beach & pool
5th-best month of the year

May is a reasonable time to visit Spa for sightseeing.

What to pack for Spa in May

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

In May, Spa sees daytime highs around 17°C and nights near 8°C. Pack rain gear. Worth having: a warm layer and sun protection. About 14 days see rain.

rain geara warm layersun protection

UV index in Spa in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 6 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Spa peaks around July 16 at about 7 (high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near January 1 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 7 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighModerateLowJul 16UV 7Jan 1UV 1
UV index (midday)Level
Jan1Low
Feb1Low
Mar3Moderate
Apr4Moderate
May6High
Jun6High
Jul7High
Aug6High
Sep4Moderate
Oct3Moderate
Nov1Low
Dec1Low

Air quality in Spa 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 Spa is worst in April — around 18 µg/m³ PM2.5 (moderate), about 1.7× the cleanest month (November, 11 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodApr 1218 µg/m³Nov 2211 µg/m³
PM2.5 (µg/m³)Level
Jan14Moderate
Feb13Moderate
Mar17Moderate
Apr18Moderate
May15Moderate
Jun14Moderate
Jul13Moderate
Aug14Moderate
Sep13Moderate
Oct12Good
Nov11Good
Dec11Good
Location & terrain

Where is Spa?

Spa sits at 50.5°N, 5.9°E, 0 m above sea level, in Belgium. The nearest listed city is Heusy, 10 km away.

SoumagneHerveFléronChaudfontaineEupenGrivegnée

Topography around Spa

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

Within 3 km, the terrain around Spa has significant variations in elevation — a maximum elevation change of 353 m around an average of 369 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 615 m; within 80 km, large variations in elevation — a maximum elevation change of 1,001 m.

The land around Spa is covered by trees (79%) within 3 km, trees (61%) and grassland (33%) within 16 km, and trees (43%), grassland (26%) and cropland (24%) within 80 km.

3 km
353 m
16 km
615 m
80 km
1,001 m
treesgrasslandcroplandartificial surfaceswater
May weather nearby: Heusy 10 km · Verviers 12 km · Soumagne 17 km · Herve 18 km · Fléron 20 km · Chaudfontaine 20 km · Eupen 20 km · Grivegnée 24 km

Belgium travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type C / E
230 V · 50 Hz
Prices
≈ 81% of US
price level, 2025
GDP per capita
$60,750
2025
Happiness
6.9 / 10
World Happiness, 2025
Safe drinking water
100%
of population, 2024
Homicide rate
1.1
per 100k, 2021
Road deaths
5.8
per 100k/yr, 2019
Income group
High
World Bank
English
Very high
EF EPI 608
Religion
Roman Catholic 57%nonbeliever/agnostic 20%atheist 9%Muslim 7%

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 Spa (50.4838°, 5.8667°, elevation 0 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).