Heidelberg weather in December

In December, Heidelberg sees average daytime highs of 26°C and overnight lows near 15°C, with 140 mm of rain across 17 wet days and about 13.6 hours of daylight. It is the 2nd-warmest and 1st-wettest month of the year here.

Day-to-day highs hold fairly steady near 26°C through the month. The sky is clear or mostly clear about 29% of the time in December, and the air most often feels comfortable.

Daylight stretches from about 13 h 30 min at the start of December to 13 h 36 min by month's end. Set against the rest of the year, December is Heidelberg's 12th-clearest and 5th-windiest month. For the whole year in context, see Heidelberg's year-round climate.

Daytime high
26°
2nd warmest
Overnight low
15°
10th coldest
Rainfall
140 mm
17 wet days
Daylight
13 h 42 min
5:13 AM – 6:52 PM
Cloud cover
57%
12th clearest
Wind
11 km/h
5th windiest
Solar energy
6.84 kWh/m²
Travel score
5.7
out of 10

Heidelberg is town in Gauteng province, South Africa.

Founded
1886

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 26°C through the month.

A typical December day in Heidelberg reaches about 26°C in the afternoon and slips back to 15°C overnight — a 11°C spread between the day's warmth and the night's chill. On most days the high lands between 22°C and 30°C. Set against its neighbours, December runs on par with November and on par with January.

10°15°20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
12615
22615
32615
42615
52615
62615
72615
82615
92615
102615
112615
122615
132615
142615
152615
162615
172615
182615
192616
202616
212616
222616
232616
242616
252616
262616
272616
282616
292616
302616
312616

How December really feels in Heidelberg

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.

Heidelberg weather by month

How December compares with the rest of the year at a glance. December is the 2nd-warmest and 1st-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan26° / 16°1291613.55.9
Feb26° / 16°10012.812.96.2
Mar25° / 14°8411.512.26.9
Apr23° / 11°416.811.47.6
May21° / 152.710.78.2
Jun18° / 71.510.48.0
Jul18° / 30.710.58.1
Aug21° / 112.111.18.6
Sep25° / 10°223.611.88.5
Oct26° / 13°7810.512.67.0
Nov26° / 14°10113.813.36.2
Dec26° / 15°1401713.65.7

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 29% of the time in December, the cloudiest month of the year.

Beyond those clear spells, partly cloudy skies cover about 27% of December, with mostly cloudy or overcast conditions the remaining 44%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15446
25446
35446
45446
55446
65446
75545
85545
95545
105644
115644
125644
135644
145743
155743
165743
175842
185842
195842
205743
215743
225644
235644
245545
255545
265545
275743
285743
295842
305842
315941

Chance of precipitation in December

Any precipitation

Heidelberg gets around 140 mm of rain over 17 wet days in December, the wettest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 54% and peaks near 57% on the wettest days.

0%20%40%60%151015202531
Rain chance (%)
153
254
355
456
556
657
757
857
957
1057
1156
1256
1356
1455
1554
1654
1753
1852
1952
2052
2152
2252
2353
2453
2553
2653
2753
2853
2953
3053
3153

Humidity in December

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, December lands in the comfortable band about 52% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)
152426
250446
349456
447467
546477
644487
743498
842508
941518
1040528
1139538
1238548
1337558
1436559
1535569
16355510
17345610
18335611
19325612
20315514
21305515
22295516
23285418
24275419
25275320
26265321
27255322
28255223
29245224
30245125
31245026

Wind in December

Winds average 11 km/h in December.

Across December, daily wind ranges from about 11 km/h on the calmest days to 12 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202531
Wind speed (km/h)Feels
112calm
212calm
312calm
412calm
511calm
611calm
711calm
811calm
911calm
1011calm
1111calm
1211calm
1311calm
1411calm
1511calm
1611calm
1711calm
1811calm
1911calm
2011calm
2111calm
2211calm
2311calm
2411calm
2511calm
2611calm
2711calm
2811calm
2911calm
3011calm
3111calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 13 h 30 min at the start of December to 13 h 36 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 6 minutes over December. Sunrise moves from 5:10 AM to 5:20 AM, and sunset from 6:43 PM to 6:59 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.55:106:43
213.65:106:43
313.65:106:44
413.65:106:45
513.65:106:45
613.65:106:46
713.65:116:47
813.65:116:47
913.65:116:48
1013.65:116:49
1113.65:126:49
1213.65:126:50
1313.65:126:51
1413.65:126:51
1513.75:136:52
1613.75:136:52
1713.75:136:53
1813.75:146:53
1913.75:146:54
2013.75:156:55
2113.75:156:55
2213.75:166:55
2313.75:166:56
2413.75:176:56
2513.75:176:57
2613.75:186:57
2713.75:186:58
2813.75:196:58
2913.75:196:58
3013.65:206:59
3113.65:206:59

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 6.84 kWh/m² — the sunniest month for solar.

For context, solar energy here swings from a low near 3.89 kWh/m² to a high of 6.84 kWh/m² in December across the year — December's 6.84 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
16.8Intense
26.8Intense
36.8Intense
46.8Intense
56.8Intense
66.8Intense
76.8Intense
86.8Intense
96.8Intense
106.8Intense
116.8Intense
126.8Intense
136.8Intense
146.9Intense
156.9Intense
166.9Intense
176.9Intense
186.9Intense
196.9Intense
206.9Intense
216.9Intense
226.9Intense
236.9Intense
246.9Intense
256.9Intense
266.9Intense
276.9Intense
286.9Intense
296.9Intense
306.9Intense
316.9Intense
Planning a trip in December

Hazard calendar for Heidelberg

In seasonPeak

In December, Heidelberg sits inside its rainy season season. The full year is below, with each hazard's peak months called out.

Heidelberg'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 December a good time to visit Heidelberg?

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

5.7
Sightseeing
12th-best month of the year
5.5
Beach & pool
8th-best month of the year

December is a reasonable time to visit Heidelberg for sightseeing.

What to pack for Heidelberg in December

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

In December, Heidelberg sees daytime highs around 26°C and nights near 15°C. Pack rain gear and sun protection. Worth having: light clothes. About 17 days see rain.

rain gearsun protectionlight clothes

UV index in Heidelberg in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December 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 Heidelberg peaks around January 12 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 20 at about 5 (high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highHighVery highExtremeJan 12UV 14Jun 20UV 5
UV index (midday)Level
Jan14Extreme
Feb13Extreme
Mar12Extreme
Apr9Very high
May6High
Jun5High
Jul6High
Aug7Very high
Sep9Very high
Oct10Extreme
Nov12Extreme
Dec14Extreme

Air quality in Heidelberg 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 Heidelberg is worst in June — around 259 µg/m³ PM2.5 (very unhealthy), about 6.0× the cleanest month (January, 43 µg/m³).

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

0306090120150180210240270JanFebMarAprMayJunJulAugSepOctNovDecPoorUnhealthyVery unhealthyUnhealthyPoorJun 23259 µg/m³Jan 1344 µg/m³
PM2.5 (µg/m³)Level
Jan43Poor
Feb63Unhealthy
Mar101Unhealthy
Apr158Very unhealthy
May232Very unhealthy
Jun259Very unhealthy
Jul259Very unhealthy
Aug200Very unhealthy
Sep144Unhealthy
Oct91Unhealthy
Nov65Unhealthy
Dec50Poor
Location & terrain

Where is Heidelberg?

Heidelberg sits at 26.5°S, 28.4°E, 1,525 m above sea level, in South Africa. The nearest listed city is Nigel, 14 km away.

Topography around Heidelberg

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

Within 3 km, the terrain around Heidelberg has only modest variations in elevation — a maximum elevation change of 239 m around an average of 1,557 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 440 m; within 80 km, large variations in elevation — a maximum elevation change of 665 m.

The land around Heidelberg is covered by grassland (51%) and artificial surfaces (28%) within 3 km, grassland (60%) and cropland (30%) within 16 km, and grassland (50%) and cropland (34%) within 80 km.

3 km
239 m
16 km
440 m
80 km
665 m
treesshrubsgrasslandcroplandartificial surfacesbare terrainwater
December weather nearby: Nigel 14 km · Tokoza 28 km · Springs 29 km · Balfour 29 km · Brakpan 30 km · Boksburg 34 km · Germiston 35 km · Alberton 35 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
Christian 86%or other traditional African religions 5%nothing in particular 5%Muslim 2%

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 Heidelberg (-26.5048°, 28.3592°, elevation 1,525 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).