Heilbron in Summer
In summer (December, January and February), Heilbron sees average daytime highs around 27°C and overnight lows near 16°C, with 350 mm of rain over about 44 wet days across the season. It is the warmest season of the year and the wettest season of the year.
Across summer, daytime highs hold fairly steady around 27°C. The sky is clear or mostly clear about 40% of the time across summer, and the air most often feels comfortable.
Summer is Heilbron's weakest season of the year to visit on our travel score. For the whole year in context, see Heilbron's year-round climate.
- Avg daytime high
- 27°C
- warmest season of the year
- Avg overnight low
- 16°C
- Rainfall
- 350 mm
- 44 wet days
- Avg wind
- 11 km/h
- Travel score
- 6.0
- weakest season of the year
- Months
- Dec · Jan · Feb
Temperature in Heilbron in Summer
Across summer, daytime highs hold fairly steady around 27°C.
A typical summer day in Heilbron reaches about 27°C and drops to 16°C overnight. The warmest of the three months is January, the coolest December.
How summer really feels in Heilbron
Once humidity and wind are folded in, summer brings about 0 days that feel above 32°C and 0 that feel at or below 0°C.
summer sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.
Heilbron weather by month
How the three summer months (December, January and February) compare with the rest of the year — the season's months are highlighted.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 27° / 16° | 124 | 15 | 13.5 | 5.9 |
| Feb | 27° / 16° | 87 | 12.6 | 13 | 6.2 |
| Mar | 25° / 14° | 81 | 11.1 | 12.2 | 6.9 |
| Apr | 23° / 11° | 43 | 6.9 | 11.4 | 7.7 |
| May | 21° / 7° | 19 | 3.1 | 10.7 | 8.1 |
| Jun | 18° / 3° | 10 | 1.7 | 10.3 | 7.8 |
| Jul | 18° / 3° | 6 | 1.1 | 10.5 | 7.9 |
| Aug | 21° / 6° | 15 | 2.4 | 11 | 8.4 |
| Sep | 25° / 10° | 20 | 3.2 | 11.8 | 8.6 |
| Oct | 26° / 13° | 76 | 9.8 | 12.7 | 7.1 |
| Nov | 26° / 14° | 98 | 12.5 | 13.3 | 6.4 |
| Dec | 27° / 15° | 139 | 16.6 | 13.7 | 5.8 |
Cloud cover in Summer
The sky is clear or mostly clear about 40% of the time across summer.
Chance of precipitation in Summer
Heilbron gets around 350 mm of rain over 44 wet days across summer. The line is the day-by-day chance of measurable precipitation.
Humidity in Summer
Most of summer feels comfortable — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Summer
Winds average 11 km/h across summer.
Sunrise & sunset in Summer
Daylight runs from about 13 h 36 min in early December to 12 h 36 min by late February. The lit band spans sunrise to sunset each day.
Solar energy in Summer
Average shortwave solar energy reaching the ground each day across summer, about 6.8 kWh/m².
Hazard calendar for Heilbron
In summer, Heilbron overlaps its rainy season season. The full year is below, with each hazard's peak months called out.
Heilbron's rainy season runs October–March, when most of the year's rain falls.
Is summer a good time to visit Heilbron?
Our two travel scores rate summer for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
summer is a reasonable time to visit Heilbron for sightseeing.
What to pack for Heilbron in Summer
From summer's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In summer, Heilbron sees daytime highs around 27°C and nights near 16°C. Pack rain gear and sun protection. Worth having: light clothes. About 44 days see rain.
UV index in Heilbron in Summer
Clear-sky midday UV across summer averages 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 Heilbron peaks around January 14 at about 15 (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.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 15 | 13 | 11 | 8 | 6 | 5 | 5 | 7 | 9 | 10 | 12 | 14 |
| Level | Extreme | Extreme | Extreme | Very high | High | Moderate | High | Very high | Very high | Extreme | Extreme | Extreme |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 15 | Extreme |
| Feb | 13 | Extreme |
| Mar | 11 | Extreme |
| Apr | 8 | Very high |
| May | 6 | High |
| Jun | 5 | Moderate |
| Jul | 5 | High |
| Aug | 7 | Very high |
| Sep | 9 | Very high |
| Oct | 10 | Extreme |
| Nov | 12 | Extreme |
| Dec | 14 | Extreme |
Air quality in Heilbron in Summer
Average fine-particle pollution (PM2.5) through the year — so you can see where summer falls, not just the annual average.
Air quality in Heilbron is worst in July — around 103 µg/m³ PM2.5 (unhealthy), about 4.4× the cleanest month (January, 24 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) | 24 | 32 | 48 | 64 | 88 | 100 | 103 | 83 | 65 | 44 | 31 | 25 |
| Level | Moderate | Moderate | Poor | Unhealthy | Unhealthy | Unhealthy | Unhealthy | Unhealthy | Unhealthy | Poor | Moderate | Moderate |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 24 | Moderate |
| Feb | 32 | Moderate |
| Mar | 48 | Poor |
| Apr | 64 | Unhealthy |
| May | 88 | Unhealthy |
| Jun | 100 | Unhealthy |
| Jul | 103 | Unhealthy |
| Aug | 83 | Unhealthy |
| Sep | 65 | Unhealthy |
| Oct | 44 | Poor |
| Nov | 31 | Moderate |
| Dec | 25 | Moderate |
Where is Heilbron?
Heilbron sits at 27.3°S, 28.0°E, 1,539 m above sea level, in South Africa. The nearest listed city is Koppies, 39 km away.
Topography around Heilbron
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Heilbron.
Within 3 km, the terrain around Heilbron has only modest variations in elevation — a maximum elevation change of 83 m around an average of 1,555 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 268 m; within 80 km, significant variations in elevation — a maximum elevation change of 455 m.
The land around Heilbron is covered by grassland (56%) and cropland (22%) within 3 km, grassland (51%) and cropland (47%) within 16 km, and grassland (56%) and cropland (40%) within 80 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 Heilbron (-27.2812°, 27.9709°, elevation 1,539 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.