Nam Som weather in May

In May, Nam Som sees average daytime highs of 33°C and overnight lows near 25°C, with 236 mm of rain across 23.1 wet days and about 12.8 hours of daylight. It is the 3rd-warmest and 4th-wettest month of the year here.

Highs ease over the month, from about 34°C in the first days to 33°C by the end. The sky is clear or mostly clear about 11% of the time in May, and the air most often feels miserable.

Daylight stretches from about 12 h 36 min at the start of May to 13 hours by month's end. Set against the rest of the year, May is Nam Som's 8th-clearest and 10th-windiest month. For the whole year in context, see Nam Som's year-round climate.

Daytime high
33°
3rd warmest
Overnight low
25°
10th coldest
Rainfall
236 mm
23.1 wet days
Daylight
12 h 48 min
5:43 AM – 6:32 PM
Cloud cover
78%
8th clearest
Wind
5 km/h
10th windiest
Solar energy
5.27 kWh/m²
Travel score
2.3
out of 10

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 34°C in the first days to 33°C by the end.

A typical May day in Nam Som reaches about 33°C in the afternoon and slips back to 25°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between 30°C and 37°C. Set against its neighbours, May runs about 2°C cooler than April and about 1°C warmer than June.

20°25°30°35°40°151015202531
Avg high (°C)Avg low (°C)
13425
23425
33425
43425
53425
63425
73425
83425
93425
103425
113325
123325
133325
143325
153325
163325
173325
183325
193325
203325
213325
223325
233325
243325
253325
263325
273325
283325
293325
303325
313325

How May really feels in Nam Som

Once humidity and wind are folded in, May averages 31 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
31
31 feel dangerously hot (≥ 39°C)
Days feeling ≤ C
0
wind chill below the day's low

The story in May is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

Nam Som weather by month

How May compares with the rest of the year at a glance. May is the 3rd-warmest and 4th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan29° / 17°101.611.17.1
Feb31° / 18°142.411.45.5
Mar34° / 22°396.911.93.6
Apr35° / 24°7812.812.42.5
May33° / 25°23623.112.82.3
Jun32° / 25°23122.8132.4
Jul32° / 25°26824.9132.5
Aug31° / 25°32626.312.62.6
Sep31° / 24°26624.412.12.8
Oct31° / 23°10512.311.64.4
Nov30° / 20°232.911.26.1
Dec28° / 17°91.3117.7

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 11% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 12% of May, with mostly cloudy or overcast conditions the remaining 77%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14852
24753
34456
44258
54060
63862
73664
83466
93367
103169
112971
122674
132476
142278
152179
162080
171882
181783
191585
201387
211387
221189
231189
241189
251090
261090
271090
28991
29991
30793
31694

Chance of precipitation in May

Any precipitation

Nam Som gets around 236 mm of rain over 23.1 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 74% and peaks near 84% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%80%151015202531
Rain chance (%)
159
260
361
462
563
664
765
866
968
1069
1171
1272
1373
1474
1575
1676
1777
1878
1979
2080
2180
2281
2382
2482
2583
2683
2784
2884
2984
3084
3184

Humidity in May

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, May lands in the miserable band about 52% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202531
Humid (%)Muggy (%)Oppressive (%)Miserable (%)
11107019
21106821
3096724
4086626
5086428
6076231
7075934
8065836
9065539
10065341
11055144
12054846
13054748
14054550
15044353
16044254
17044056
18033958
19033760
20023662
21023563
22023365
23023266
24013069
25012970
26012772
27012574
28012475
29002278
30002179
31002080

Wind in May

Winds average 5 km/h in May.

Across May, daily wind ranges from about 5 km/h on the calmest days to 6 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (km/h)Feels
16calm
26calm
36calm
46calm
56calm
66calm
75calm
85calm
95calm
105calm
115calm
125calm
135calm
145calm
155calm
165calm
175calm
185calm
195calm
205calm
215calm
225calm
235calm
245calm
255calm
265calm
275calm
285calm
295calm
305calm
315calm

Sunrise & sunset in May

DaylightNight

Daylight runs from about 12 h 36 min at the start of May to 13 hours by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 24 minutes over May. Sunrise moves from 5:49 AM to 5:39 AM, and sunset from 6:27 PM to 6:38 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
112.65:496:27
212.65:496:28
312.75:486:28
412.75:486:28
512.75:476:29
612.75:476:29
712.75:466:29
812.75:466:30
912.75:456:30
1012.85:456:30
1112.85:446:31
1212.85:446:31
1312.85:446:31
1412.85:436:32
1512.85:436:32
1612.85:436:32
1712.85:426:33
1812.95:426:33
1912.95:426:34
2012.95:416:34
2112.95:416:34
2212.95:416:35
2312.95:416:35
2412.95:406:35
2512.95:406:36
2612.95:406:36
2712.95:406:36
2813.05:406:37
2913.05:406:37
3013.05:396:38
3113.05:396:38

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.27 kWh/m².

For context, solar energy here swings from a low near 4.2 kWh/m² to a high of 6.03 kWh/m² in April across the year — May's 5.27 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
15.8Bright
25.8Bright
35.7Bright
45.7Bright
55.7Bright
65.6Bright
75.6Bright
85.5Bright
95.5Bright
105.5Bright
115.4Bright
125.4Bright
135.3Bright
145.3Bright
155.3Bright
165.2Bright
175.2Bright
185.2Bright
195.1Bright
205.1Bright
215.1Bright
225.1Bright
235.0Bright
245.0Bright
255.0Bright
265.0Bright
275.0Bright
285.0Bright
294.9Bright
304.9Bright
314.9Bright
Planning a trip in May

Hazard calendar for Nam Som

In seasonPeak

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

Nam Som's monsoon runs May–September, when most of the year's rain falls.

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

Is May a good time to visit Nam Som?

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

2.3
Sightseeing
12th-best month of the year
4.2
Beach & pool
9th-best month of the year

May is a weaker month for outdoor sightseeing in Nam Som.

What to pack for Nam Som in May

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

In May, Nam Som sees daytime highs around 33°C and nights near 25°C. Pack light clothes and rain gear. Worth having: sun protection. About 23 days see rain.

light clothesrain gearsun protection

UV index in Nam Som in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 11 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Nam Som peaks around August 12 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 14 at about 8 (very high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecVery highExtremeVery highAug 12UV 13Dec 14UV 8
UV index (midday)Level
Jan9Very high
Feb10Very high
Mar12Extreme
Apr11Extreme
May11Extreme
Jun13Extreme
Jul13Extreme
Aug13Extreme
Sep11Extreme
Oct10Extreme
Nov8Very high
Dec8Very high

Air quality in Nam Som 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 Nam Som is worst in April — around 122 µg/m³ PM2.5 (unhealthy), about 8.3× the cleanest month (November, 15 µg/m³).

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

0306090120150JanFebMarAprMayJunJulAugSepOctNovDecModerateUnhealthyModerateApr 11119 µg/m³Nov 1615 µg/m³
PM2.5 (µg/m³)Level
Jan22Moderate
Feb37Poor
Mar108Unhealthy
Apr122Unhealthy
May28Moderate
Jun16Moderate
Jul15Moderate
Aug16Moderate
Sep15Moderate
Oct16Moderate
Nov15Moderate
Dec17Moderate
Location & terrain

Where is Nam Som?

Nam Som sits at 17.8°N, 102.2°E, 231 m above sea level, in Thailand. The nearest listed city is Tha Bo, 42 km away.

Topography around Nam Som

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

Within 3 km, the terrain around Nam Som has only modest variations in elevation — a maximum elevation change of 156 m around an average of 227 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 559 m; within 80 km, large variations in elevation — a maximum elevation change of 951 m.

The land around Nam Som is covered by trees (51%) and cropland (36%) within 3 km, trees (66%) and cropland (28%) within 16 km, and trees (59%) and cropland (34%) within 80 km.

3 km
156 m
16 km
559 m
80 km
951 m
treesgrasslandcroplandartificial surfaceswater
May weather nearby: Tha Bo 42 km · Vientiane 49 km · Na Klang 52 km · Kut Chap 55 km · Erawan 58 km · Loei 58 km · Nong Khai 60 km · Nong Bua Lamphu 68 km

Thailand travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type A / B / C
230 V · 50 Hz
Prices
≈ 31% of US
price level, 2025
GDP per capita
$8,057
2025
Happiness
6.3 / 10
World Happiness, 2025
Homicide rate
4.8
per 100k, 2011
Road deaths
32.2
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
Very low
EF EPI 402
Religion
Buddhist 93%Muslim 5%Christian 1%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 Nam Som (17.7704°, 102.1895°, elevation 231 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).