Climate averages 1991–2020
Sliven weather
in September.
A warm, moderately wet month: the 4th warmest and the joint 4th driest of the year. Meets the pleasant-weather rule
Long-term climate patterns, not a forecast for a particular trip.
September is a warm month in Sliven: daytime highs average 23.4°C and nights cool to about 14.1°C. By daytime temperature it is the 4th warmest of the 12 months.
Expect about 58 mm of rain on roughly 8 days, which makes September a moderately wet month (the joint 4th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 32 min on an average September day.
The nearest other city in this atlas is Stara Zagora (63 km away). In September its highs average 24.3°C, 0.9°C warmer than Sliven, with 47 mm of rain.
Among the 10 cities listed in Bulgaria, Sliven ranks 6th of 10 for the warmest September highs and 10th of 10 for the driest September (rainfall, lowest first). The mean September high of those 10 cities is 23.2°C; Sliven is 0.2°C warmer than that mean.
From September to October, average highs fall by 5.8°C to 17.6°C, and monthly rainfall rises from 58 mm to 63 mm.
The annual picture
September in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Sliven climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 5.4°C-1.4°C | -1.4°C | 53 | 7.7 | 9.49 h |
| February | 7.4°C-0.5°C | -0.5°C | 54 | 8.1 | 10.511 h |
| March | 11.2°C2.2°C | 2.2°C | 67 | 10.7 | 11.912 h |
| April | 16.4°C6.6°C | 6.6°C | 75 | 12.2 | 13.413 h |
| May | 21.4°C11.6°C | 11.6°C | 106 | 14.5 | 14.615 h |
| June | 25.3°C15.8°C | 15.8°C | 100 | 14.0 | 15.315 h |
| July | 27.7°C17.9°C | 17.9°C | 88 | 11.6 | 15.015 h |
| August | 28.1°C17.9°C | 17.9°C | 56 | 8.0 | 13.914 h |
| September, selected | 23.4°C14.1°C | 14.1°C | 58 | 7.8 | 12.513 h |
| October | 17.6°C9.6°C | 9.6°C | 63 | 7.8 | 11.111 h |
| November | 11.8°C4.8°C | 4.8°C | 58 | 7.4 | 9.810 h |
| December | 6.5°C0.2°C | 0.2°C | 63 | 8.6 | 9.19 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
September in nearby cities
- Stara Zagora in SeptemberBulgaria · 63 kmHigh 24.3°C · Low 14.0°C · 47 mm rain
- Shumen in SeptemberBulgaria · 81 kmHigh 22.5°C · Low 12.9°C · 50 mm rain
- Burgas in SeptemberBulgaria · 96 kmHigh 23.5°C · Low 15.2°C · 50 mm rain
- Edirne in SeptemberTurkey · 114 kmHigh 26.6°C · Low 15.0°C · 27 mm rain
- Ruse in SeptemberBulgaria · 133 kmHigh 24.1°C · Low 14.5°C · 55 mm rain
- Varna in SeptemberBulgaria · 142 kmHigh 22.6°C · Low 15.8°C · 48 mm rain
- Plovdiv in SeptemberBulgaria · 142 kmHigh 23.9°C · Low 13.8°C · 42 mm rain
- Pleven in SeptemberBulgaria · 161 kmHigh 24.3°C · Low 14.4°C · 47 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Sliven) is explained once on the Sliven year overview and on the Sources, method and limits page.