La Unión weather in May

In May, La Unión sees average daytime highs of 24°C and overnight lows near 15°C, with 311 mm of rain across 24.8 wet days and about 12.3 hours of daylight. It is the 5th-warmest and 4th-wettest month of the year here.

Day-to-day highs hold fairly steady near 24°C through the month. The sky is clear or mostly clear about 0% of the time in May, and the air most often feels humid.

Daylight stretches from about 12 h 12 min at the start of May to 12 h 18 min by month's end. Set against the rest of the year, May is La Unión's 11th-clearest and 8th-windiest month. For the whole year in context, see La Unión's year-round climate.

Daytime high
24°
5th warmest
Overnight low
15°
12th coldest
Rainfall
311 mm
24.8 wet days
Daylight
12 h 18 min
5:50 AM – 6:06 PM
Cloud cover
93%
11th clearest
Wind
3 km/h
8th windiest
Solar energy
5.02 kWh/m²
Travel score
4.3
out of 10

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 24°C through the month.

A typical May day in La Unión reaches about 24°C in the afternoon and slips back to 15°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 21°C and 26°C. Set against its neighbours, May runs on par with April and on par with June.

10°15°20°25°30°151015202531
Avg high (°C)Avg low (°C)
12415
22415
32415
42415
52415
62415
72415
82415
92415
102415
112415
122415
132415
142415
152415
162415
172415
182415
192415
202415
212415
222415
232414
242414
252414
262414
272414
282414
292414
302414
312414

La Unión weather by month

How May compares with the rest of the year at a glance. May is the 5th-warmest and 4th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan23° / 14°16122.311.74.8
Feb23° / 14°19022.511.84.4
Mar23° / 14°30926.9124.1
Apr23° / 15°35225.512.14.0
May24° / 15°31124.812.34.3
Jun24° / 14°13016.912.35.3
Jul25° / 14°8511.812.36.1
Aug25° / 14°11113.112.25.8
Sep24° / 14°21621.6124.7
Oct23° / 14°3672811.93.8
Nov23° / 14°40228.811.73.6
Dec23° / 14°24324.511.74.4

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 0% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 2% of May, with mostly cloudy or overcast conditions the remaining 98%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
1199
2199
3199
4199
5199
6199
7199
8199
9298
10298
11298
12298
13298
14298
15298
16298
17298
18298
19298
20298
21298
22298
23298
24298
25298
26397
27397
28397
29496
30496
31496

Chance of precipitation in May

Any precipitation

La Unión gets around 311 mm of rain over 24.8 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 79% and peaks near 83% on the wettest days.

0%20%40%60%80%151015202531
Rain chance (%)
183
282
382
481
581
680
780
879
979
1078
1178
1277
1377
1477
1577
1677
1777
1877
1978
2078
2179
2279
2380
2480
2580
2679
2779
2878
2977
3076
3175

Humidity in May

DryComfortableHumidMuggyOppressiveMiserable

Most of May feels humid — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, May lands in the humid band about 54% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)
103961
203961
303961
404060
504060
604060
704060
804159
904159
1004159
1104159
1204258
1304258
1404258
1504357
1604456
1704555
1804555
1904654
2004753
2104852
2204852
2304951
2404951
2505149
2615049
2715247
2815346
2915445
3015544
3115742

Wind in May

Winds average 3 km/h in May.

Across May, daily wind ranges from about 3 km/h on the calmest days to 3 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (km/h)Feels
13calm
23calm
33calm
43calm
53calm
63calm
73calm
83calm
93calm
103calm
113calm
123calm
133calm
143calm
153calm
163calm
173calm
183calm
193calm
203calm
213calm
223calm
233calm
243calm
253calm
263calm
273calm
283calm
293calm
303calm
313calm

Sunrise & sunset in May

DaylightNight

Daylight runs from about 12 h 12 min at the start of May to 12 h 18 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 6 minutes over May. Sunrise moves from 5:52 AM to 5:49 AM, and sunset from 6:05 PM to 6:08 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
112.25:526:05
212.25:526:05
312.25:526:05
412.25:526:05
512.25:516:05
612.25:516:05
712.25:516:05
812.25:516:05
912.25:516:05
1012.25:506:05
1112.35:506:05
1212.35:506:05
1312.35:506:05
1412.35:506:06
1512.35:506:06
1612.35:506:06
1712.35:496:06
1812.35:496:06
1912.35:496:06
2012.35:496:06
2112.35:496:07
2212.35:496:07
2312.35:496:07
2412.35:496:07
2512.35:496:07
2612.35:496:07
2712.35:496:08
2812.35:496:08
2912.35:496:08
3012.35:496:08
3112.35:496:08

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.02 kWh/m².

For context, solar energy here swings from a low near 4.3 kWh/m² to a high of 6.22 kWh/m² in August across the year — May's 5.02 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
14.9Bright
24.9Bright
34.9Bright
44.9Bright
54.9Bright
65.0Bright
75.0Bright
85.0Bright
95.0Bright
105.0Bright
115.0Bright
125.0Bright
135.0Bright
145.0Bright
155.0Bright
165.0Bright
175.1Bright
185.1Bright
195.1Bright
205.1Bright
215.1Bright
225.1Bright
235.1Bright
245.1Bright
255.1Bright
265.1Bright
275.2Bright
285.2Bright
295.2Bright
305.2Bright
315.3Bright
Planning a trip in May

Is May a good time to visit La Unión?

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

4.3
Sightseeing
8th-best month of the year
3.7
Beach & pool
6th-best month of the year

May is a reasonable time to visit La Unión for sightseeing.

What to pack for La Unión in May

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

In May, La Unión sees daytime highs around 24°C and nights near 15°C. Pack rain gear. Worth having: light clothes and sun protection. About 25 days see rain.

rain gearlight clothessun protection

UV index in La Unión in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 14 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in La Unión peaks around February 21 at about 16 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 13 at about 12 (extreme).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeFeb 21UV 16Dec 13UV 12
UV index (midday)Level
Jan13Extreme
Feb16Extreme
Mar16Extreme
Apr12Extreme
May14Extreme
Jun12Extreme
Jul13Extreme
Aug13Extreme
Sep14Extreme
Oct14Extreme
Nov12Extreme
Dec12Extreme

Air quality in La Unión 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 La Unión is worst in March — around 33 µg/m³ PM2.5 (moderate), about 1.9× the cleanest month (October, 17 µg/m³).

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

010203040JanFebMarAprMayJunJulAugSepOctNovDecModerateMar 1631 µg/m³Oct 2217 µg/m³
PM2.5 (µg/m³)Level
Jan19Moderate
Feb25Moderate
Mar33Moderate
Apr24Moderate
May20Moderate
Jun18Moderate
Jul18Moderate
Aug21Moderate
Sep18Moderate
Oct17Moderate
Nov17Moderate
Dec18Moderate
Location & terrain

Where is La Unión?

La Unión sits at 6.0°N, 75.4°W, 2,475 m above sea level, in Colombia. The nearest listed city is La Ceja, 10 km away.

Topography around La Unión

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

Within 3 km, the terrain around La Unión has significant variations in elevation — a maximum elevation change of 274 m around an average of 2,485 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,898 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,673 m.

The land around La Unión is covered by grassland (68%) and trees (23%) within 3 km, trees (56%) and grassland (41%) within 16 km, and trees (66%) and grassland (33%) within 80 km.

3 km
274 m
16 km
1,898 m
80 km
3,673 m
treesgrasslandcroplandartificial surfacesbare terrainwater
May weather nearby: La Ceja 10 km · Carmen de Viboral 12 km · Retiro 18 km · Rionegro 20 km · Santuario 21 km · Abejorral 22 km · Marinilla 22 km · Sonsón 30 km

Colombia travel facts

Travel advisory
Level 3
Reconsider Travel
Power plugs
Type A / B
120 / 240 V · 60 Hz
Prices
≈ 38% of US
price level, 2025
GDP per capita
$8,562
2025
Happiness
6.0 / 10
World Happiness, 2025
Safe drinking water
74%
of population, 2024
Homicide rate
24.9
per 100k, 2023
Road deaths
15.4
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
Low
EF EPI 480
Religion
Roman Catholic 64%Protestant 17%none 14%atheist 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 La Unión (5.9743°, -75.3619°, elevation 2,475 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).