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Sliven, Bulgaria climate
Cfa Humid subtropical
Sliven has a seasonal mild-temperate climate (Humid subtropical, Köppen Cfa). The hottest month is August with an average daily high near 31°C, while the coldest is January averaging around −1°C at night. Around 626 mm of precipitation falls each year, peaking in June (81 mm) and easing off in April (37 mm).
Temperature & precipitation
Daily high–low temperature range with the monthly average, plus monthly precipitation · 1991–2020 normals · hover a month for the exact figuresHours of sunshine per day
Estimated sunny hours each month — daylight length × clear-sky fraction · 1991–2020 monthly cloud cover (NASA POWER)Sliven climate normals (1991–2020)
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°C) | 6 | 9 | 13 | 18 | 23 | 27 | 30 | 31 | 26 | 19 | 13 | 7 |
| Avg temp (°C) | 3 | 4 | 8 | 13 | 18 | 22 | 24 | 25 | 20 | 14 | 9 | 4 |
| Avg low (°C) | −1 | 0 | 3 | 7 | 12 | 16 | 19 | 19 | 14 | 10 | 5 | 0 |
| Precipitation (mm) | 42 | 42 | 48 | 37 | 79 | 81 | 61 | 39 | 51 | 48 | 44 | 55 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Avg high (°C) | 6 | 9 | 13 | 18 | 23 | 27 |
| Avg temp (°C) | 3 | 4 | 8 | 13 | 18 | 22 |
| Avg low (°C) | −1 | 0 | 3 | 7 | 12 | 16 |
| Precipitation (mm) | 42 | 42 | 48 | 37 | 79 | 81 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Avg high (°C) | 30 | 31 | 26 | 19 | 13 | 7 |
| Avg temp (°C) | 24 | 25 | 20 | 14 | 9 | 4 |
| Avg low (°C) | 19 | 19 | 14 | 10 | 5 | 0 |
| Precipitation (mm) | 61 | 39 | 51 | 48 | 44 | 55 |
Sky & atmosphere
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cloud cover (%) | 68 | 69 | 69 | 65 | 61 | 52 | 41 | 38 | 51 | 61 | 67 | 70 |
| Relative humidity (%) | 86 | 82 | 77 | 73 | 68 | 62 | 54 | 52 | 61 | 73 | 82 | 86 |
| Wind speed (m/s) | 2.1 | 2.3 | 2.3 | 2.1 | 1.9 | 1.8 | 1.9 | 2.0 | 2.0 | 2.0 | 2.0 | 2.1 |
| Jan – Jun | Jan | Feb | Mar | Apr | May | Jun |
|---|---|---|---|---|---|---|
| Cloud cover (%) | 68 | 69 | 69 | 65 | 61 | 52 |
| Relative humidity (%) | 86 | 82 | 77 | 73 | 68 | 62 |
| Wind speed (m/s) | 2.1 | 2.3 | 2.3 | 2.1 | 1.9 | 1.8 |
| Jul – Dec | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|
| Cloud cover (%) | 41 | 38 | 51 | 61 | 67 | 70 |
| Relative humidity (%) | 54 | 52 | 61 | 73 | 82 | 86 |
| Wind speed (m/s) | 1.9 | 2.0 | 2.0 | 2.0 | 2.0 | 2.1 |
Methodology & sources
Temperature & precipitation — 1991–2020 normals computed from 29 years of daily observations at Sliven, a weather station, about 2 km from the city centre. The underlying daily records come from NOAA's global station network.
Cloud, humidity, wind & sunshine — modelled estimates from NASA POWER, NASA's satellite-and-reanalysis climatology. This is the standard global source for atmospheric variables, which are not measured at most weather stations.