Nan weather in December

In December, Nan sees average daytime highs of 29°C and overnight lows near 17°C, with 14 mm of rain across 1.7 wet days and about 10.9 hours of daylight. It is the 12th-warmest and 11th-wettest month of the year here.

Day-to-day highs hold fairly steady near 29°C through the month. The sky is clear or mostly clear about 62% of the time in December, and the air most often feels humid.

Daylight stretches from about 11 hours at the start of December to 10 h 54 min by month's end. Set against the rest of the year, December is Nan's 4th-clearest and 9th-windiest month. For the whole year in context, see Nan's year-round climate.

Daytime high
29°
12th warmest
Overnight low
17°
2nd coldest
Rainfall
14 mm
1.7 wet days
Daylight
10 h 54 min
6:47 AM – 5:39 PM
Cloud cover
34%
4th clearest
Wind
4 km/h
9th windiest
Solar energy
4.37 kWh/m²
Travel score
6.6
out of 10

Nan is town in Nan province, Thailand.

Air quality
High
PM2.5 29.5 µg/m³ · 2019

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

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 29°C through the month.

A typical December day in Nan reaches about 29°C in the afternoon and slips back to 17°C overnight — a 12°C spread between the day's warmth and the night's chill. On most days the high lands between 26°C and 32°C. Set against its neighbours, December runs about 2°C cooler than November and on par with January.

10°15°20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
13019
23019
33018
43018
53018
63018
73018
83018
93018
103018
113018
123017
133017
142917
152917
162917
172917
182917
192917
202916
212916
222916
232916
242916
252916
262916
272916
282916
292916
302916
312916

How December really feels in Nan

Once humidity and wind are folded in, December 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

December sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Nan weather by month

How December compares with the rest of the year at a glance. December is the 12th-warmest and 11th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan30° / 16°152116.4
Feb33° / 17°81.211.44.7
Mar35° / 20°304.611.92.9
Apr36° / 24°7811.612.42.2
May34° / 25°16621.512.92.3
Jun32° / 25°19023.413.12.5
Jul31° / 25°27326.5132.6
Aug31° / 24°31228.112.62.6
Sep31° / 24°22124.412.12.8
Oct31° / 23°7413.811.64.1
Nov31° / 20°223.511.15.4
Dec29° / 17°141.710.96.6

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 62% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 17% of December, with mostly cloudy or overcast conditions the remaining 21%. Skies tend to open up as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
17822
27723
37723
47723
57624
67624
77624
87525
97525
107525
117624
127624
137723
147723
157822
167921
178020
188020
198119
208218
218218
228317
238317
248317
258218
268218
278218
288218
298119
308020
318020

Chance of precipitation in December

Any precipitation

Nan gets around 14 mm of rain over 1.7 wet days in December. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 6% and peaks near 9% on the wettest days.

0%10%20%30%151015202531
Rain chance (%)
19
28
38
48
58
67
77
87
96
106
115
125
135
144
154
164
174
184
194
204
214
225
235
245
255
266
276
286
297
307
317

Humidity in December

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, December lands in the humid band about 39% of days. Sticky, muggy-or-worse air turns up on roughly 26% of them.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
141037409
251137398
351238378
451338368
551339357
661440337
761540327
861641316
961742296
1071942285
1172042274
1282142264
1382242243
1492441233
15102541223
16112640212
17122740202
18122839192
19132939182
20143038171
21143138161
22143238151
23153237151
24153337141
25153337141
26153438131
27143438131
28143439131
29133440131
30123440131
31113441131

Wind in December

Winds average 4 km/h in December.

Across December, daily wind ranges from about 4 km/h on the calmest days to 4 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (km/h)Feels
14calm
24calm
34calm
44calm
54calm
64calm
74calm
84calm
94calm
104calm
114calm
124calm
134calm
144calm
154calm
164calm
174calm
184calm
194calm
204calm
214calm
224calm
234calm
244calm
254calm
264calm
274calm
284calm
294calm
304calm
314calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 11 hours at the start of December to 10 h 54 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 6 minutes over December. Sunrise moves from 6:38 AM to 6:54 AM, and sunset from 5:35 PM to 5:47 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
111.06:385:35
210.96:395:35
310.96:395:35
410.96:405:36
510.96:415:36
610.96:415:36
710.96:425:36
810.96:425:37
910.96:435:37
1010.96:435:37
1110.96:445:38
1210.96:455:38
1310.96:455:38
1410.96:465:39
1510.96:465:39
1610.96:475:39
1710.96:475:40
1810.96:485:40
1910.96:485:41
2010.96:495:41
2110.96:495:41
2210.96:505:42
2310.96:505:42
2410.96:515:43
2510.96:515:43
2610.96:525:44
2710.96:525:44
2810.96:525:45
2910.96:535:45
3010.96:535:46
3110.96:545:47

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 4.37 kWh/m².

For context, solar energy here swings from a low near 3.85 kWh/m² to a high of 6.22 kWh/m² in April across the year — December's 4.37 kWh/m² falls in the middle.

012345151015202531
Solar energy (kWh/m²)Level
14.3Bright
24.3Bright
34.3Bright
44.3Bright
54.3Bright
64.3Bright
74.3Bright
84.3Bright
94.3Bright
104.3Bright
114.3Bright
124.3Bright
134.3Bright
144.4Bright
154.4Bright
164.4Bright
174.4Bright
184.4Bright
194.4Bright
204.4Bright
214.4Bright
224.4Bright
234.5Bright
244.5Bright
254.5Bright
264.5Bright
274.4Bright
284.4Bright
294.4Bright
304.4Bright
314.4Bright
Planning a trip in December

Hazard calendar for Nan

In seasonPeak

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

Nan'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 December a good time to visit Nan?

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

6.6
Sightseeing
1st-best month of the year
8.7
Beach & pool
1st-best month of the year

December is a reasonable time to visit Nan for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Nan in December

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

In December, Nan sees daytime highs around 29°C and nights near 17°C. Pack light clothes.

light clothes

UV index in Nan in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December 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 Nan peaks around August 12 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 17 at about 7 (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 17UV 7
UV index (midday)Level
Jan8Very high
Feb9Very high
Mar9Very high
Apr10Very high
May11Extreme
Jun13Extreme
Jul13Extreme
Aug13Extreme
Sep11Extreme
Oct10Very high
Nov8Very high
Dec7High

Air quality in Nan in December

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where December falls, not just the annual average.

Air quality in Nan is worst in March — around 71 µg/m³ PM2.5 (unhealthy), about 4.2× the cleanest month (September, 17 µg/m³).

Seasonal pattern from CAMS reanalysis, scaled to Nan's WHO annual average of 29.5 µg/m³.

020406080JanFebMarAprMayJunJulAugSepOctNovDecModeratePoorUnhealthyModerateMar 2270 µg/m³Sep 1517 µg/m³
PM2.5 (µg/m³)Level
Jan27Moderate
Feb39Poor
Mar71Unhealthy
Apr65Unhealthy
May28Moderate
Jun17Moderate
Jul17Moderate
Aug17Moderate
Sep17Moderate
Oct17Moderate
Nov18Moderate
Dec21Moderate
Location & terrain

Where is Nan?

Nan sits at 18.8°N, 100.8°E, 205 m above sea level, in Thailand. The nearest listed city is Dok Kham Tai, 93 km away.

Dok Kham TaiPhraePhayaoDen ChaiLampangUttaraditChiang RaiBan Houakhoua

Topography around Nan

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

Within 3 km, the terrain around Nan has only modest variations in elevation — a maximum elevation change of 61 m around an average of 208 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 478 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,915 m.

The land around Nan is covered by trees (39%), artificial surfaces (28%) and cropland (21%) within 3 km, trees (76%) within 16 km, and trees (87%) within 80 km.

3 km
61 m
16 km
478 m
80 km
1,915 m
treesgrasslandcroplandartificial surfacesbare terrainwater
December weather nearby: Dok Kham Tai 93 km · Phrae 98 km · Phayao 105 km · Den Chai 117 km · Lampang 146 km · Uttaradit 148 km · Chiang Rai 160 km · Ban Houakhoua 166 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 Nan (18.7838°, 100.779°, elevation 205 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).