Sliven in Summer
In summer (June, July and August), Sliven sees average daytime highs around 26°C and overnight lows near 16°C, with 245 mm of rain over about 34 wet days across the season. It is the warmest season of the year and the 2nd-wettest season.
Over the season highs climb from about 22°C in early June to 26°C by late August. The sky is clear or mostly clear about 51% of the time across summer, and the air most often feels comfortable.
Summer is Sliven's best season of the year to visit on our travel score. For the whole year in context, see Sliven's year-round climate.
- Avg daytime high
- 26°C
- warmest season of the year
- Avg overnight low
- 16°C
- Rainfall
- 245 mm
- 34 wet days
- Avg wind
- 7 km/h
- Travel score
- 6.7
- best season of the year
- Months
- Jun · Jul · Aug
Temperature in Sliven in Summer
Over the season highs climb from about 22°C in early June to 26°C by late August.
A typical summer day in Sliven reaches about 26°C and drops to 16°C overnight. The warmest of the three months is August, the coolest June.
How summer really feels in Sliven
Once humidity and wind are folded in, summer brings about 0 days that feel above 32°C and 0 that feel at or below 0°C.
summer sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.
Sliven weather by month
How the three summer months (June, July and August) compare with the rest of the year — the season's months are highlighted.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Snow days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|---|
| Jan | 3° / -3° | 53 | 7.7 | 5.1 | 9.2 | 0.0 |
| Feb | 6° / -2° | 54 | 8 | 5.1 | 10.3 | 0.3 |
| Mar | 10° / 1° | 67 | 10.7 | 4.3 | 11.6 | 2.0 |
| Apr | 15° / 6° | 75 | 12.3 | 0.9 | 13.1 | 4.2 |
| May | 20° / 10° | 106 | 14.5 | 0 | 14.4 | 5.7 |
| Jun | 24° / 14° | 100 | 14 | 0 | 15.1 | 6.3 |
| Jul | 27° / 16° | 89 | 11.7 | 0 | 14.8 | 6.7 |
| Aug | 27° / 16° | 56 | 8 | 0 | 13.7 | 7.2 |
| Sep | 22° / 12° | 58 | 7.8 | 0 | 12.3 | 7.3 |
| Oct | 16° / 8° | 63 | 7.8 | 0.4 | 10.8 | 5.4 |
| Nov | 10° / 3° | 58 | 7.4 | 2.1 | 9.6 | 2.3 |
| Dec | 5° / -1° | 63 | 8.6 | 4.5 | 8.9 | 0.1 |
Cloud cover in Summer
The sky is clear or mostly clear about 51% of the time across summer.
Chance of precipitation in Summer
Sliven gets around 245 mm of rain over 34 wet days across summer. The line is the day-by-day chance of measurable precipitation.
Humidity in Summer
Most of summer feels comfortable — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Summer
Winds average 7 km/h across summer.
Sunrise & sunset in Summer
Daylight runs from about 14 h 54 min in early June to 13 h 06 min by late August. The lit band spans sunrise to sunset each day.
Solar energy in Summer
Average shortwave solar energy reaching the ground each day across summer, about 6.3 kWh/m².
Is summer a good time to visit Sliven?
Our two travel scores rate summer for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
summer is a reasonable time to visit Sliven for sightseeing. The water and warmth also suit a beach or pool day.
What to pack for Sliven in Summer
From summer's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In summer, Sliven sees daytime highs around 26°C and nights near 16°C. Pack light clothes, rain gear and sun protection. About 34 days see rain.
UV index in Sliven in Summer
Clear-sky midday UV across summer averages around 8 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Sliven peaks around July 17 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 21 at about 1 (low).
The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 1 | 2 | 3 | 8 | 6 | 8 | 9 | 8 | 6 | 4 | 2 | 1 |
| Level | Low | Moderate | Moderate | Very high | High | Very high | Very high | Very high | High | Moderate | Low | Low |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 1 | Low |
| Feb | 2 | Moderate |
| Mar | 3 | Moderate |
| Apr | 8 | Very high |
| May | 6 | High |
| Jun | 8 | Very high |
| Jul | 9 | Very high |
| Aug | 8 | Very high |
| Sep | 6 | High |
| Oct | 4 | Moderate |
| Nov | 2 | Low |
| Dec | 1 | Low |
Air quality in Sliven in Summer
Average fine-particle pollution (PM2.5) through the year — so you can see where summer falls, not just the annual average.
Air quality in Sliven is worst in March — around 16 µg/m³ PM2.5 (moderate), about 1.6× the cleanest month (September, 10 µg/m³).
Modeled monthly averages (CAMS reanalysis, 2015–2024).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 13 | 14 | 16 | 15 | 13 | 13 | 12 | 11 | 10 | 10 | 11 | 11 |
| Level | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Good | Good | Good | Good | Good | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 13 | Moderate |
| Feb | 14 | Moderate |
| Mar | 16 | Moderate |
| Apr | 15 | Moderate |
| May | 13 | Moderate |
| Jun | 13 | Moderate |
| Jul | 12 | Good |
| Aug | 11 | Good |
| Sep | 10 | Good |
| Oct | 10 | Good |
| Nov | 11 | Good |
| Dec | 11 | Good |
Where is Sliven?
Sliven sits at 42.7°N, 26.3°E, 281 m above sea level, in Bulgaria. The nearest listed city is Yambol, 27 km away.
Topography around Sliven
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Sliven.
Within 3 km, the terrain around Sliven has significant variations in elevation — a maximum elevation change of 598 m around an average of 351 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 1,041 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,510 m.
The land around Sliven is covered by trees (43%), artificial surfaces (33%) and grassland (21%) within 3 km, trees (52%) and cropland (29%) within 16 km, and trees (42%) and cropland (40%) within 80 km.
Bulgaria travel facts
- Travel advisory
- Level 1
- Exercise Normal Precautions
- Power plugs
- Type C / F
- 230 V · 50 Hz
- Prices
- ≈ 23% of US
- price level, 2025
- GDP per capita
- $20,328
- 2025
- Happiness
- 5.7 / 10
- World Happiness, 2025
- Safe drinking water
- 96%
- of population, 2024
- Homicide rate
- 1.1
- per 100k, 2023
- Road deaths
- 9.2
- per 100k/yr, 2019
- Income group
- High
- World Bank
- English
- High
- EF EPI 594
- Religion
Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.
Data sources
Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Sliven (42.6861°, 26.3256°, elevation 281 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google.