Average temperature in January is -2.4 °C
Average daytime temperature is 0.4 °C
Average night temperature is -5.2 °C
Absolute maximum temperature: 9.4 °C
Absolute minimum temperature: -18.3 °C
Number of sunny days: 23
Number of rainy days: 5
Number of snow days: 3
Precipitation sum: 18 mm
* Weather data for Sumy Ukraine is based on climate observations for 2023 year
| January (°C) | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Maximum temperature | 9.2 | 9.4 | 7.9 | 4.6 | 3.2 | 1.2 | -13.2 | -10 | -5.8 | -6.3 | -6.1 | -3.5 | -1.4 | -0.3 | -1.2 | -0.1 | 2.9 | 5.1 | 9.3 | 7 | 1.1 | 0.9 | 1.5 | 1.1 | 0.2 | -1.2 | 1.2 | -0.3 | -2.6 | -0.4 | -0.5 |
| Apparent max temperature | 5.6 | 6.2 | 4.1 | -0.9 | -0.1 | -2.5 | -18.2 | -14.7 | -11.9 | -13.2 | -12.5 | -8.6 | -6.2 | -4.7 | -5.7 | -5.6 | -2.5 | -0.7 | 4.7 | 2.9 | -4.8 | -3 | -3.2 | -3.3 | -3.2 | -5.6 | -3 | -5.6 | -6.9 | -6.6 | -5.7 |
| Mean temperature | 7 | 6.9 | 5.9 | 2.1 | 1.2 | -7.4 | -16 | -13.8 | -8.7 | -9.1 | -9.1 | -5.8 | -2.8 | -2.1 | -3.2 | -2.5 | 1.4 | 4.1 | 6.5 | 3.7 | -0.5 | -0.9 | -3.2 | -4.2 | -3.7 | -3.6 | -3 | -4.3 | -4.2 | -2.7 | -2 |
| Apparent mean temperature | -1.2 | 1.3 | -1.4 | -5.3 | -5.8 | -21 | -22.4 | -22.8 | -18.7 | -18.5 | -19.1 | -14.5 | -9.5 | -7.1 | -9.5 | -9.6 | -6.3 | -2.6 | -0.5 | -6.4 | -8.2 | -7.4 | -10.2 | -11.1 | -11.7 | -11.6 | -10.8 | -11.8 | -10.8 | -9.6 | -9.1 |
| Minimum temperature | 3 | 4.4 | 4 | -0.9 | -1.3 | -15.5 | -17.5 | -18.3 | -13.2 | -11.5 | -12.3 | -8.9 | -4.7 | -3.1 | -4.8 | -4.7 | -0.7 | 2.8 | 4.3 | -0.7 | -1.7 | -3.2 | -5.6 | -6.8 | -7.7 | -7.3 | -7.1 | -6.8 | -6.5 | -5.1 | -3.7 |
| Apparent min temperature | 3.1 | 3.8 | 1.8 | -3.3 | -3.3 | -13.1 | -21.1 | -18.7 | -14.6 | -16.4 | -15.4 | -11.2 | -7.4 | -6.4 | -7.6 | -7.5 | -4.5 | -1.5 | 1.7 | -1.4 | -6.3 | -4.9 | -7.7 | -8.5 | -7.2 | -7.4 | -7.1 | -9.2 | -8.6 | -8.1 | -6.7 |
| January | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight duration (h) | 8 | 8 | 8.1 | 8.1 | 8.1 | 8.1 | 8.2 | 8.2 | 8.2 | 8.3 | 8.3 | 8.3 | 8.4 | 8.4 | 8.4 | 8.5 | 8.5 | 8.5 | 8.6 | 8.6 | 8.7 | 8.7 | 8.8 | 8.8 | 8.9 | 8.9 | 9 | 9 | 9.1 | 9.1 | 9.2 |
| Sunshine duration (h) | 2 | 4.1 | 5.3 | 1.7 | 0 | 2.5 | 6.7 | 6.6 | 4.7 | 6.7 | 6.1 | 6.8 | 0 | 0 | 0.6 | 0 | 0 | 1.3 | 4 | 6.5 | 4.7 | 0.1 | 6.8 | 7.5 | 5.9 | 1 | 6 | 7.1 | 2.2 | 6.1 | 0 |
| Precipitation (mm) | 1.3 | 0 | 0 | 0 | 7.6 | 0.7 | 0 | 0 | 0.3 | 0 | 0 | 0 | 0 | 0 | 0 | 0.6 | 2.5 | 3.5 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1.8 |
| Precipitation hours | 6 | 0 | 0 | 0 | 17 | 6 | 0 | 0 | 3 | 0 | 0 | 0 | 0 | 0 | 0 | 5 | 10 | 8 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 15 |
| Wind speed (m/s) | 21.6 | 20.9 | 23.4 | 30.1 | 25.7 | 23.2 | 10.2 | 12.5 | 18.2 | 28.9 | 23.9 | 18.6 | 18.3 | 13.9 | 14.3 | 21.2 | 29.1 | 30.5 | 27.6 | 25.5 | 23.7 | 10.8 | 12 | 10 | 6.8 | 9.4 | 13.4 | 16.3 | 10.7 | 22.9 | 17.8 |
In January 2023, the highest daytime temperature in Sumy was 9.4°C.
While the minimum temperature at night dropped to -18.3°C.
The average nighttime and daytime temperatures during January in Sumy are -5.2°C and 0.4°C respectively.
The precipitation sum in January is about 18 mm.