Heidelberg, South Africa Climate
The warmest month is February, with an average high of 28°C; the coldest is July, with an average low of 2°C. A normal year brings 653 mm of precipitation.
Temperature through the year
The normal daily high and low. The line marks today.
- Normal low
- Normal high
- Reanalysis extreme high
- Reanalysis extreme low
Normals for Sep 24
- Normal high
- 27°C
- Normal low
- 9°C
- Reanalysis high
- 32°Cin 1998
- Reanalysis low
- 5°Cin 2012
- Chance of a wet day
- 14%
- Daylight
- 12 h 10 min
Month by month
Averages for 1991-2020. Wet days have at least 1 mm of precipitation in the reanalysis. Each month links to its own page.
| Month | Avg high | Avg low | Warmest | Coldest | Precipitation | Wet days |
|---|---|---|---|---|---|---|
| January | 28°C | 14°C | 39°C (2016) | 6°C (1998) | 112 mm | 18.6 |
| February | 28°C | 14°C | 36°C (1998) | 7°C (2007) | 82 mm | 14.1 |
| March | 27°C | 13°C | 35°C (1999) | 5°C (2003) | 78 mm | 12.4 |
| April | 24°C | 9°C | 31°C (1998) | 0°C (2007) | 36 mm | 6.0 |
| May | 21°C | 5°C | 29°C (2012) | -6°C (2007) | 12 mm | 3.1 |
| June | 18°C | 2°C | 25°C (1998) | -6°C (2010) | 6 mm | 0.0 |
| July | 18°C | 2°C | 26°C (2002) | -6°C (2000) | 3 mm | 0.0 |
| August | 22°C | 4°C | 30°C (2015) | -6°C (2003) | 9 mm | 3.1 |
| September | 26°C | 8°C | 33°C (1997) | -3°C (2013) | 15 mm | 3.0 |
| October | 28°C | 11°C | 35°C (2011) | 2°C (2003) | 74 mm | 12.4 |
| November | 27°C | 12°C | 36°C (2015) | 4°C (2002) | 99 mm | 15.0 |
| December | 28°C | 14°C | 36°C (2018) | 2°C (1994) | 127 mm | 21.7 |
| Year | 25°C | 9°C | 653 mm | 109 |
Precipitation
Rain and melted snow together. The chance of a wet day is the share of days with at least 1 mm of precipitation in the reanalysis.
653 mm in a normal year, most in December.
Chance of a wet day
- Chance of a wet day
Humidity and comfort
NASA POWER reanalysis, 1991-2020, for the grid cell around Heidelberg.
Days with a mean dew point of 18°C or more are rare here in every month.
| Month | Dew point | Humidity | Dry | Comfortable | Humid | Muggy | Oppressive | Miserable |
|---|---|---|---|---|---|---|---|---|
| January | 13°C | 66% | 39% | 50% | 11% | 0% | 0% | 0% |
| February | 13°C | 66% | 48% | 44% | 8% | 0% | 0% | 0% |
| March | 11°C | 65% | 73% | 25% | 2% | 0% | 0% | 0% |
| April | 7°C | 63% | 97% | 3% | 0% | 0% | 0% | 0% |
| May | 2°C | 57% | 100% | 0% | 0% | 0% | 0% | 0% |
| June | -1°C | 56% | 100% | 0% | 0% | 0% | 0% | 0% |
| July | -2°C | 52% | 100% | 0% | 0% | 0% | 0% | 0% |
| August | -1°C | 46% | 100% | 0% | 0% | 0% | 0% | 0% |
| September | 1°C | 41% | 100% | 0% | 0% | 0% | 0% | 0% |
| October | 6°C | 52% | 97% | 3% | 0% | 0% | 0% | 0% |
| November | 10°C | 60% | 79% | 21% | 1% | 0% | 0% | 0% |
| December | 12°C | 65% | 52% | 44% | 4% | 0% | 0% | 0% |
Comfort is judged by the day's mean dew point: dry below 13°C, comfortable to 16°C, humid to 18°C, muggy to 21°C, oppressive to 24°C, miserable above.
Clouds
Average share of the sky covered, from satellite (CERES and GEWEX SRB) by way of NASA POWER, 1991-2020.
The clearest month is July, with the sky 22 percent covered on average; the cloudiest is December, at 67 percent.
Wind
The mean wind speed over the whole day, from the MERRA-2 reanalysis by way of NASA POWER. Gusts run well above it.
The windiest month is September, averaging 16.2 km/h at 10 meters (33 feet) above the ground.
Daylight and sunshine
The longest day is Dec 18, with 13 h 49 min of daylight; the shortest is Jun 18, with 10 h 28 min.
- Day length
Solar energy
Average daily sunshine reaching the ground on a flat surface, in kilowatt-hours per square meter, clouds included.
Month pages
The weather in Heidelberg in each month, day by day.
What this means
A normal is the average of the thirty years 1991 to 2020, the period the World Meteorological Organization and NOAA use for comparison. It is an average, not a forecast: most days depart from it, and some by a long way.
Where no station record is within reach, the extremes shown are the highest and lowest the reanalysis produced for the date in 1991-2020, not measured records.
Cloud, humidity, wind and sunshine come from a reanalysis: a weather model run over the past with every observation fed in, averaged over a grid cell about 50 km across. It is consistent everywhere on Earth; it smooths local detail such as a lake shore or a valley.
More for this place
Nearby
Sources
Cloud, humidity, wind and sunshine, and temperature and precipitation: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-24. Sun and moon: computed with the NOAA solar equations and Meeus.