Heilbron climate — normals and trends
Heilbron (South Africa) has a subtropical highland, dry winter climate (Cwb) under the Köppen-Geiger classification. Its mean annual temperature is 15.8 °C and it receives 812 mm of precipitation per year.
These figures are normals computed over 86 complete calendar years, from 1940 to 2025, using ERA5 reanalysis data from the Copernicus programme.
The warmest month is January (20.4 °C on average) and the coldest is June (8.7 °C). Rainfall peaks in January.
Heilbron averages 10 frost days, 22 hot days (≥ 30 °C) and 107 rainy days per year.
Heilbron has warmed by +1.5 °C between 1940 and 2025, or +0.18 °C per decade. This trend is statistically significant.
The hottest day of the period reached 39.3 °C (on 6 January 2016) and the coldest -5.7 °C (on 14 July 1990).
Data from ERA5 reanalysis (Copernicus Climate Change Service), redistributed under a CC-BY 4.0 licence. Normals are recomputed whenever the archive is updated.
Climate normals · ERA5
HeilbronFree State
- coords
- -27.28°, 27.97°
- period
- 1940–2025 · 86 yrs
Mean daily temperature
15.8°C
Average daily high
22.9°C
Average daily low
10.2°C
Annual rainfall
812mm
Sunshine / day
10.8h
Mean relative humidity
61%
Average peak wind
18.1km/h
Seasonal range
11.7°C
Frost days (< 0 °C)
10 d/yr
Hot days (≥ 30 °C)
22 d/yr
Rainy days (≥ 1 mm)
107 d/yr
Annual snowfall
0.4 cm
Average feels-like high
21.7 °C
Average feels-like low
8.0 °C
Average peak gust
35.8 km/h
Tropical nights (≥ 20 °C)
0 d/yr
Solar radiation
20.2 MJ/m²
Has the climate changed?
One stripe per year, 1940 to 2025
+1.5 °C
since 1940
+0.2 °C per decade · r² = 0.38 · p = < 0.001
Trend fitted by linear regression (ordinary least squares) on annual means. A trend is shown only when it is statistically significant (p < 0.05).
A climograph overlays rainfall (bars) and temperature (line): the standard reading in climatology, where you can see at a glance whether the warm season is also the dry one.
Records for the period
Hottest day
39.3 °C
6 January 2016
Coldest day
-5.7 °C
14 July 1990
Wettest day
117 mm
17 December 1995
Windiest day
48.0 km/h
23 September 1941
Strongest gust
88.2 km/h
23 October 1995
Hottest feels-like
38.3 °C
6 January 2016
Coldest feels-like
-9.9 °C
26 June 1992
Snowiest day
11.1 cm
7 July 1996
Sunniest day
13.7 h
24 December 2025
Normals computed over complete calendar years 1940–2025.
A specific year
Pick a year and see how it compares to normal — warmer, drier or more extreme than usual?
Across the whole year
Month by month
| High | vs. normal | Precipitation | vs. normal | |
|---|---|---|---|---|
| Jan | 27.6 °C | +1.2 °C | 157 mm | +17 mm |
| Feb | 26.3 °C | +0.5 °C | 232 mm | +122 mm |
| Mar | 24.7 °C | 0.0 °C | 134 mm | +43 mm |
| Apr | 21.0 °C | -1.3 °C | 204 mm | +146 mm |
| May | 20.5 °C | +0.6 °C | 10 mm | -12 mm |
| Jun | 17.9 °C | +0.8 °C | 10 mm | +1 mm |
| Jul | 17.9 °C | +0.6 °C | 12 mm | +7 mm |
| Aug | 22.6 °C | +2.3 °C | 28 mm | +14 mm |
| Sep | 24.6 °C | +0.6 °C | 49 mm | +22 mm |
| Oct | 25.6 °C | +0.2 °C | 69 mm | -9 mm |
| Nov | 23.4 °C | -2.3 °C | 230 mm | +110 mm |
| Dec | 25.5 °C | -0.8 °C | 128 mm | -11 mm |
The year's extremes
What was the weather like that day?
Your birthday, a wedding, a memorable trip: discover the actual weather for any date since 1940.
Frequently asked questions
What is the climate of Heilbron?
Heilbron has a subtropical highland, dry winter climate (Köppen Cwb). Over 1940-2025, the average annual temperature is 15.8 °C and it receives 812 mm of precipitation per year.
What is the hottest day ever recorded in Heilbron?
The hottest day measured in Heilbron between 1940 and 2025 was 6 January 2016, reaching 39.3 °C.
What is the coldest day in Heilbron?
The coldest day measured in Heilbron between 1940 and 2025 was 14 July 1990, at -5.7 °C.
Does it snow in Heilbron?
Almost never: Heilbron sees virtually no snow, with about 10 frost days per year.
Has the climate of Heilbron warmed?
Yes: Heilbron warmed by +1.5 °C between 1940 and 2025, a statistically significant trend.
What is the wettest day in Heilbron?
The wettest day measured in Heilbron between 1940 and 2025 was 17 December 1995, with 117 mm of rain in 24 hours.
What was the windiest day in Heilbron?
The windiest day measured in Heilbron between 1940 and 2025 was 23 September 1941, with winds reaching 48.0 km/h.
What is the warmest month in Heilbron?
The warmest month in Heilbron is January (20.4 °C on average); the coldest is June (8.7 °C).
How much does it rain in Heilbron?
Heilbron receives on average 812 mm of precipitation per year, spread over about 107 rainy days.
Is it sunny in Heilbron?
Heilbron gets on average 10.8 hours of sunshine per day, roughly 3,942 hours per year over 1940-2025.
What is the biggest single-day snowfall in Heilbron?
The heaviest 24-hour snowfall measured in Heilbron between 1940 and 2025 was 7 July 1996, with 11.1 cm.
Are there tropical nights in Heilbron?
Almost never: tropical nights (temperature staying above 20 °C) are virtually non-existent in Heilbron.
What was the most extreme apparent temperature in Heilbron?
In Heilbron, between 1940 and 2025, the highest apparent temperature reached 38.3 °C on 6 January 2016, and the lowest was -9.9 °C on 26 June 1992.
Compare Heilbron with another city
Pick a second city: its normals will be set against these, indicator by indicator.
Nearby cities
The climate around Heilbron