Average annual temperature is 10.9 °C
Absolute maximum temperature: 30.2 °C
Absolute minimum temperature: -6.7 °C
Number of sunny days: 109 days
Number of rainy days: 251 days
Number of snow days: 5 days
Look at detailed online map of Sy
* Weather data for Sy Belgium is based on climate observations for 2026 year
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Absolute maximum temperature (°C) | 13.6 | 13.1 | 14.3 | 18.1 | 22.6 | 28.0 | 30.2 | 27.9 | 28.7 | 24.6 | 14.1 | 10.5 |
| Average daytime temperature (°C) | 5.5 | 7.6 | 9.1 | 11.5 | 16.8 | 23.7 | 21.6 | 20.8 | 22.1 | 16.0 | 8.5 | 6.9 |
| Average temperature (°C) | 3.5 | 4.4 | 6.1 | 7.5 | 12.5 | 19.2 | 17.7 | 17.1 | 17.7 | 12.6 | 6.5 | 5.2 |
| Average night temperature (°C) | 1.4 | 1.7 | 2.8 | 3.5 | 7.6 | 13.8 | 13.3 | 13.0 | 13.0 | 9.5 | 4.6 | 3.5 |
| Absolute minimum temperature (°C) | -6.7 | -4.1 | -4.5 | -3.3 | 2.3 | 8.7 | 9.3 | 9.5 | 7.2 | 0.8 | -3.3 | -4.5 |
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight maximum duration (h) | 9.0 | 10.0 | 12.0 | 14.0 | 16.0 | 16.0 | 16.0 | 15.0 | 13.0 | 11.0 | 9.0 | 8.0 |
| Daylight mean duration (h) | 8.6 | 10.1 | 11.9 | 13.8 | 15.5 | 16.3 | 15.9 | 14.5 | 12.6 | 10.7 | 9.0 | 8.1 |
| Daylight minimum duration (h) | 8.0 | 9.0 | 10.0 | 12.0 | 14.0 | 16.0 | 15.0 | 13.0 | 11.0 | 9.0 | 8.0 | 8.0 |
| Sunshine mean duration (h) | 2.6 | 5.1 | 5.1 | 7.5 | 10.7 | 13.3 | 10.5 | 9.2 | 9.6 | 5.9 | 2.9 | 2.3 |
| Precipitation (mm) | 124 | 34 | 161 | 86 | 48 | 82 | 131 | 140 | 60 | 105 | 156 | 108 |
| Sunny days | 7 | 13 | 4 | 7 | 12 | 19 | 8 | 5 | 18 | 9 | 2 | 5 |
| Rainy days | 20 | 15 | 27 | 23 | 19 | 11 | 23 | 26 | 12 | 22 | 28 | 25 |
| Snow days | 4 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
The best time to visit Sy during the most sunny months:
Months with the longest average daylight duration in Sy:
The largest precipitation sum in Sy is at