Belfast weather in May

In May, Belfast sees average daytime highs of 19°C and overnight lows near 6°C, with 14 mm of precipitation across 2.5 wet days and about 10.8 hours of daylight. It is the 10th-warmest and 9th-wettest month of the year here.

Highs ease over the month, from about 20°C in the first days to 18°C by the end. The sky is clear or mostly clear about 76% of the time in May, and the air most often feels dry.

Daylight stretches from about 11 hours at the start of May to 10 h 30 min by month's end. Set against the rest of the year, May is Belfast's 4th-clearest and 10th-windiest month. For the whole year in context, see Belfast's year-round climate.

Daytime high: 19°; 10th warmest
Overnight low: 6°; 4th coldest
Precipitation: 14 mm; 2.5 wet days
Daylight: 10 h 42 min; 6:34 AM – 5:19 PM
Cloud cover: 23%; 4th clearest
Wind: 10 km/h; 10th windiest
Solar energy: 4.36 kWh/m²
Travel score: 7.8; out of 10

Belfast is town in South Africa.

Founded: 1890

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

← April Belfast year-round climate June →Best places to visit in May

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

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 20°C in the first days to 18°C by the end.

A typical May day in Belfast reaches about 19°C in the afternoon and slips back to 6°C overnight — a 13°C spread between the day's warmth and the night's chill. On most days the high lands between 15°C and 22°C. Set against its neighbours, May runs about 2°C cooler than April and about 2°C warmer than June.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Avg high (°C)	20	20	20	20	20	20	20	20	20	19	19	19	19	19	19	19	19	19	19	19	19	18	18	18	18	18	18	18	18	18	18
Avg low (°C)	8	8	8	8	7	7	7	7	7	7	7	6	6	6	6	6	6	6	6	5	5	5	5	5	5	5	5	4	4	4	4

	Avg high (°C)	Avg low (°C)
1	20	8
2	20	8
3	20	8
4	20	8
5	20	7
6	20	7
7	20	7
8	20	7
9	20	7
10	19	7
11	19	7
12	19	6
13	19	6
14	19	6
15	19	6
16	19	6
17	19	6
18	19	6
19	19	6
20	19	5
21	19	5
22	18	5
23	18	5
24	18	5
25	18	5
26	18	5
27	18	5
28	18	4
29	18	4
30	18	4
31	18	4

How May really feels in Belfast

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

heat index over the day's high

Days feeling ≤ 0°C

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.

Belfast weather by month

How May compares with the rest of the year at a glance. May is the 10th-warmest and 9th-wettest month here — the current month is highlighted below.

Month	High / Low (°C)	Rainfall (mm)	Wet days	Daylight (hours)	Travel score
Jan	24° / 14°	140	17	13.4	5.9
Feb	24° / 14°	102	12.3	12.9	6.4
Mar	23° / 12°	97	11.8	12.2	6.7
Apr	21° / 10°	47	6.6	11.4	7.2
May	19° / 6°	14	2.5	10.8	7.8
Jun	17° / 3°	5	0.9	10.4	7.2
Jul	17° / 3°	6	0.8	10.6	7.2
Aug	19° / 5°	11	1.9	11.1	8.2
Sep	23° / 9°	22	4.2	11.8	8.2
Oct	23° / 11°	77	11.8	12.6	6.8
Nov	23° / 12°	122	15.6	13.3	5.9
Dec	24° / 13°	155	18.9	13.6	5.6

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 76% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 10% of May, with mostly cloudy or overcast conditions the remaining 14%. Skies tend to open up as the month goes on.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Clearer (%)	82	83	83	83	85	85	85	85	86	86	86	86	86	86	85	85	85	85	85	85	86	86	87	87	88	89	89	89	90	90	90
Cloudier (%)	18	17	17	17	15	15	15	15	14	14	14	14	14	14	15	15	15	15	15	15	14	14	13	13	12	11	11	11	10	10	10

	Clearer (%)	Cloudier (%)
1	82	18
2	83	17
3	83	17
4	83	17
5	85	15
6	85	15
7	85	15
8	85	15
9	86	14
10	86	14
11	86	14
12	86	14
13	86	14
14	86	14
15	85	15
16	85	15
17	85	15
18	85	15
19	85	15
20	85	15
21	86	14
22	86	14
23	87	13
24	87	13
25	88	12
26	89	11
27	89	11
28	89	11
29	90	10
30	90	10
31	90	10

Chance of precipitation in May

Any precipitation

Belfast gets around 14 mm of rain and snow over 2.5 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 8% and peaks near 14% on the wettest days, and about 0 day brings snow. The odds ease toward the end of the month.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Rain chance (%)	14	14	13	12	12	11	10	10	10	9	9	8	8	8	8	7	7	7	7	7	7	6	6	6	5	5	5	5	4	4	4

	Rain chance (%)
1	14
2	14
3	13
4	12
5	12
6	11
7	10
8	10
9	10
10	9
11	9
12	8
13	8
14	8
15	8
16	7
17	7
18	7
19	7
20	7
21	7
22	6
23	6
24	6
25	5
26	5
27	5
28	5
29	4
30	4
31	4

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 100% of days. It rarely turns muggy — the humid and sticky bands barely register.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Dry (%)	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100
31	100

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.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Wind speed (km/h)	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	10	10	10	10	10	10	10	10	10	10	10	10	10
Feels	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm

	Wind speed (km/h)	Feels
1	9	calm
2	9	calm
3	9	calm
4	9	calm
5	9	calm
6	9	calm
7	9	calm
8	9	calm
9	9	calm
10	9	calm
11	9	calm
12	9	calm
13	9	calm
14	9	calm
15	9	calm
16	9	calm
17	9	calm
18	9	calm
19	10	calm
20	10	calm
21	10	calm
22	10	calm
23	10	calm
24	10	calm
25	10	calm
26	10	calm
27	10	calm
28	10	calm
29	10	calm
30	10	calm
31	10	calm

Sunrise & sunset in May

DaylightNight

Daylight runs from about 11 hours at the start of May to 10 h 30 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 30 minutes over May. Sunrise moves from 6:26 AM to 6:41 AM, and sunset from 5:28 PM to 5:13 PM.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Daylight (h)	11.0	11.0	11.0	11.0	11.0	10.9	10.9	10.9	10.9	10.9	10.8	10.8	10.8	10.8	10.8	10.7	10.7	10.7	10.7	10.7	10.7	10.6	10.6	10.6	10.6	10.6	10.6	10.6	10.6	10.5	10.5
Sunrise (AM)	6:26	6:26	6:27	6:27	6:28	6:28	6:29	6:29	6:30	6:30	6:31	6:31	6:32	6:33	6:33	6:34	6:34	6:35	6:35	6:36	6:36	6:37	6:37	6:38	6:38	6:39	6:39	6:40	6:40	6:41	6:41
Sunset (PM)	5:28	5:28	5:27	5:26	5:25	5:25	5:24	5:23	5:23	5:22	5:21	5:21	5:20	5:20	5:19	5:19	5:18	5:18	5:17	5:17	5:16	5:16	5:15	5:15	5:15	5:14	5:14	5:14	5:14	5:13	5:13

	Daylight (h)	Sunrise (AM)	Sunset (PM)
1	11.0	6:26	5:28
2	11.0	6:26	5:28
3	11.0	6:27	5:27
4	11.0	6:27	5:26
5	11.0	6:28	5:25
6	10.9	6:28	5:25
7	10.9	6:29	5:24
8	10.9	6:29	5:23
9	10.9	6:30	5:23
10	10.9	6:30	5:22
11	10.8	6:31	5:21
12	10.8	6:31	5:21
13	10.8	6:32	5:20
14	10.8	6:33	5:20
15	10.8	6:33	5:19
16	10.7	6:34	5:19
17	10.7	6:34	5:18
18	10.7	6:35	5:18
19	10.7	6:35	5:17
20	10.7	6:36	5:17
21	10.7	6:36	5:16
22	10.6	6:37	5:16
23	10.6	6:37	5:15
24	10.6	6:38	5:15
25	10.6	6:38	5:15
26	10.6	6:39	5:14
27	10.6	6:39	5:14
28	10.6	6:40	5:14
29	10.6	6:40	5:14
30	10.5	6:41	5:13
31	10.5	6:41	5:13

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 4.36 kWh/m².

For context, solar energy here swings from a low near 3.98 kWh/m² to a high of 6.39 kWh/m² in December across the year — May's 4.36 kWh/m² sits near the bottom.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Solar energy (kWh/m²)	4.5	4.5	4.5	4.5	4.5	4.5	4.5	4.5	4.4	4.4	4.4	4.4	4.4	4.4	4.4	4.3	4.3	4.3	4.3	4.3	4.3	4.3	4.3	4.3	4.2	4.2	4.2	4.2	4.2	4.2	4.2
Level	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright

	Solar energy (kWh/m²)	Level
1	4.5	Bright
2	4.5	Bright
3	4.5	Bright
4	4.5	Bright
5	4.5	Bright
6	4.5	Bright
7	4.5	Bright
8	4.5	Bright
9	4.4	Bright
10	4.4	Bright
11	4.4	Bright
12	4.4	Bright
13	4.4	Bright
14	4.4	Bright
15	4.4	Bright
16	4.3	Bright
17	4.3	Bright
18	4.3	Bright
19	4.3	Bright
20	4.3	Bright
21	4.3	Bright
22	4.3	Bright
23	4.3	Bright
24	4.3	Bright
25	4.2	Bright
26	4.2	Bright
27	4.2	Bright
28	4.2	Bright
29	4.2	Bright
30	4.2	Bright
31	4.2	Bright

Planning a trip in May

Hazard calendar for Belfast

In seasonPeak

None of Belfast's seasonal hazards are active in May. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.

Belfast's rainy season runs October–March, 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 Belfast?

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

7.8

Sightseeing

3rd-best month of the year

3.2

Beach & pool

10th-best month of the year

May is one of the better times to visit Belfast for general sightseeing.

What to pack for Belfast in May

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

In May, Belfast sees daytime highs around 19°C and nights near 6°C. Worth packing: a warm layer.

a warm layer

UV index in Belfast 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 Belfast peaks around January 13 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 20 at about 6 (high).

The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
UV index (midday)	15	14	13	8	7	6	6	8	10	11	12	14
Level	Extreme	Extreme	Extreme	Very high	High	High	High	Very high	Very high	Extreme	Extreme	Extreme

	UV index (midday)	Level
Jan	15	Extreme
Feb	14	Extreme
Mar	13	Extreme
Apr	8	Very high
May	7	High
Jun	6	High
Jul	6	High
Aug	8	Very high
Sep	10	Very high
Oct	11	Extreme
Nov	12	Extreme
Dec	14	Extreme

Air quality in Belfast 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 Belfast is worst in August — around 32 µg/m³ PM2.5 (moderate), about 3.8× the cleanest month (December, 9 µg/m³).

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

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
PM2.5 (µg/m³)	10	11	13	16	21	24	30	32	27	18	13	9
Level	Good	Good	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Good

	PM2.5 (µg/m³)	Level
Jan	10	Good
Feb	11	Good
Mar	13	Moderate
Apr	16	Moderate
May	21	Moderate
Jun	24	Moderate
Jul	30	Moderate
Aug	32	Moderate
Sep	27	Moderate
Oct	18	Moderate
Nov	13	Moderate
Dec	9	Good

Location & terrain

Where is Belfast?

Belfast sits at 25.7°S, 30.0°E, 1,873 m above sea level, in South Africa. The nearest listed city is Carolina, 43 km away.

Topography around Belfast

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

Within 3 km, the terrain around Belfast has only modest variations in elevation — a maximum elevation change of 97 m around an average of 1,882 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 440 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,596 m.

The land around Belfast is covered by grassland (58%) within 3 km, grassland (71%) within 16 km, and grassland (63%) within 80 km.

3 km

97 m

grassland 58%

16 km

440 m

grassland 71%

80 km

1,596 m

grassland 63%

treesshrubsgrasslandcroplandartificial surfacesbare terrainwater

← April Belfast year-round climate June →Best places to visit in May

May weather nearby: Carolina 43 km · Middelburg 58 km · Hendrina 61 km · Breyten 68 km · Lydenburg 78 km · Emalahleni 83 km · Nhlazatje 85 km · Lukwatini 89 km

South Africa travel facts

Travel advisory: Level 2; Exercise Increased Caution
Power plugs: Type C / M / N; 230 V · 50 Hz
Prices: ≈ 41% of US; price level, 2025
GDP per capita: $6,598; 2025
Happiness: 5.0 / 10; World Happiness, 2025
Safe drinking water: 68%; of population, 2024
Homicide rate: 43.7; per 100k, 2022
Road deaths: 22.2; per 100k/yr, 2019
Income group: Upper middle; World Bank
English: Very high; EF EPI 602
Religion

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 Belfast (-25.6899°, 30.035°, elevation 1,873 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).

	Avg high (°C)	Avg low (°C)
1	20	8
2	20	8
3	20	8
4	20	8
5	20	7
6	20	7
7	20	7
8	20	7
9	20	7
10	19	7
11	19	7
12	19	6
13	19	6
14	19	6
15	19	6
16	19	6
17	19	6
18	19	6
19	19	6
20	19	5
21	19	5
22	18	5
23	18	5
24	18	5
25	18	5
26	18	5
27	18	5
28	18	4
29	18	4
30	18	4
31	18	4

	Clearer (%)	Cloudier (%)
1	82	18
2	83	17
3	83	17
4	83	17
5	85	15
6	85	15
7	85	15
8	85	15
9	86	14
10	86	14
11	86	14
12	86	14
13	86	14
14	86	14
15	85	15
16	85	15
17	85	15
18	85	15
19	85	15
20	85	15
21	86	14
22	86	14
23	87	13
24	87	13
25	88	12
26	89	11
27	89	11
28	89	11
29	90	10
30	90	10
31	90	10

	Rain chance (%)
1	14
2	14
3	13
4	12
5	12
6	11
7	10
8	10
9	10
10	9
11	9
12	8
13	8
14	8
15	8
16	7
17	7
18	7
19	7
20	7
21	7
22	6
23	6
24	6
25	5
26	5
27	5
28	5
29	4
30	4
31	4

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100
31	100

	Avg high (°C)	Avg low (°C)
1	20	8
2	20	8
3	20	8
4	20	8
5	20	7
6	20	7
7	20	7
8	20	7
9	20	7
10	19	7
11	19	7
12	19	6
13	19	6
14	19	6
15	19	6
16	19	6
17	19	6
18	19	6
19	19	6
20	19	5
21	19	5
22	18	5
23	18	5
24	18	5
25	18	5
26	18	5
27	18	5
28	18	4
29	18	4
30	18	4
31	18	4

	Clearer (%)	Cloudier (%)
1	82	18
2	83	17
3	83	17
4	83	17
5	85	15
6	85	15
7	85	15
8	85	15
9	86	14
10	86	14
11	86	14
12	86	14
13	86	14
14	86	14
15	85	15
16	85	15
17	85	15
18	85	15
19	85	15
20	85	15
21	86	14
22	86	14
23	87	13
24	87	13
25	88	12
26	89	11
27	89	11
28	89	11
29	90	10
30	90	10
31	90	10

	Rain chance (%)
1	14
2	14
3	13
4	12
5	12
6	11
7	10
8	10
9	10
10	9
11	9
12	8
13	8
14	8
15	8
16	7
17	7
18	7
19	7
20	7
21	7
22	6
23	6
24	6
25	5
26	5
27	5
28	5
29	4
30	4
31	4

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100
31	100

	Avg high (°C)	Avg low (°C)
1	20	8
2	20	8
3	20	8
4	20	8
5	20	7
6	20	7
7	20	7
8	20	7
9	20	7
10	19	7
11	19	7
12	19	6
13	19	6
14	19	6
15	19	6
16	19	6
17	19	6
18	19	6
19	19	6
20	19	5
21	19	5
22	18	5
23	18	5
24	18	5
25	18	5
26	18	5
27	18	5
28	18	4
29	18	4
30	18	4
31	18	4

	Clearer (%)	Cloudier (%)
1	82	18
2	83	17
3	83	17
4	83	17
5	85	15
6	85	15
7	85	15
8	85	15
9	86	14
10	86	14
11	86	14
12	86	14
13	86	14
14	86	14
15	85	15
16	85	15
17	85	15
18	85	15
19	85	15
20	85	15
21	86	14
22	86	14
23	87	13
24	87	13
25	88	12
26	89	11
27	89	11
28	89	11
29	90	10
30	90	10
31	90	10

	Rain chance (%)
1	14
2	14
3	13
4	12
5	12
6	11
7	10
8	10
9	10
10	9
11	9
12	8
13	8
14	8
15	8
16	7
17	7
18	7
19	7
20	7
21	7
22	6
23	6
24	6
25	5
26	5
27	5
28	5
29	4
30	4
31	4

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100
31	100