Average annual temperature is 14.0 °C
Absolute maximum temperature: 36.0 °C
Absolute minimum temperature: -4.2 °C
Number of sunny days: 206 days
Number of rainy days: 156 days
Number of snow days: 3 days
Look at detailed online map of Upper Gretna
* Weather data for Upper Gretna South Africa is based on climate observations for 2026 year
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Absolute maximum temperature (°C) | 33.1 | 30.0 | 27.7 | 25.9 | 23.1 | 19.1 | 21.0 | 22.8 | 29.6 | 30.9 | 36.0 | 32.6 |
| Average daytime temperature (°C) | 26.4 | 23.9 | 24.7 | 21.1 | 16.2 | 13.4 | 13.8 | 18.2 | 20.3 | 21.4 | 27.3 | 25.2 |
| Average temperature (°C) | 19.5 | 17.6 | 17.5 | 14.2 | 10.2 | 7.9 | 7.6 | 10.7 | 12.7 | 13.8 | 19.2 | 17.5 |
| Average night temperature (°C) | 13.1 | 12.3 | 11.2 | 8.1 | 5.2 | 3.5 | 2.2 | 3.8 | 5.2 | 7.2 | 11.1 | 11.4 |
| Absolute minimum temperature (°C) | 5.6 | 7.0 | 3.8 | 0.7 | -1.1 | -1.0 | -4.2 | -3.3 | -4.2 | 0.5 | 2.2 | 7.9 |
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight maximum duration (h) | 14.0 | 13.0 | 12.0 | 11.0 | 10.0 | 10.0 | 10.0 | 11.0 | 12.0 | 13.0 | 14.0 | 14.0 |
| Daylight mean duration (h) | 13.9 | 13.2 | 12.3 | 11.3 | 10.5 | 10.1 | 10.3 | 11.0 | 11.9 | 12.9 | 13.7 | 14.2 |
| Daylight minimum duration (h) | 13.0 | 12.0 | 11.0 | 10.0 | 10.0 | 10.0 | 10.0 | 10.0 | 11.0 | 12.0 | 13.0 | 14.0 |
| Sunshine mean duration (h) | 11.1 | 10.4 | 10.7 | 9.8 | 8.1 | 8.8 | 8.7 | 9.7 | 9.8 | 10.1 | 11.5 | 10.6 |
| Precipitation (mm) | 118 | 146 | 43 | 19 | 57 | 6 | 15 | 2 | 29 | 24 | 21 | 99 |
| Sunny days | 8 | 7 | 13 | 22 | 21 | 24 | 22 | 27 | 23 | 16 | 17 | 6 |
| Rainy days | 23 | 21 | 18 | 8 | 10 | 6 | 6 | 4 | 7 | 15 | 13 | 25 |
| Snow days | 0 | 0 | 0 | 0 | 0 | 0 | 3 | 0 | 0 | 0 | 0 | 0 |
The largest precipitation sum in Upper Gretna is at