worldweather31°Cnear normal
usually 25°C–32°C
night: exceptionally warm
rain: less rain than usual
wind: exceptionally light
Weather in Sliven - 14-day forecast
Detailed weather forecast for Sliven, Bulgaria: daytime and night temperature, rain, sunrise and sunset - today and for the next two weeks.
Forecast for the next days in Sliven
today☀️
31°night 22°
Sun☀️
29°💧 0.3 mm
Mon🌤️
28°💧 9.2 mm
Tue🌤️
25°💧 0.2 mm
Wed☀️
25°💧 0.4 mm
Thu☀️
24°💧 0.3 mm
Fri☀️
25°💧 0.8 mm
Sat☀️
29°💧 10.6 mm
Forecast vs 1991-2020 climate normal
NASA POWERHow does the current forecast compare with normal?
We compare the coming days with weather usually observed at this time of year.
Thursday 10 Sept in Sliven, the forecast high is 24°C. Typical daytime temperatures at this time of year range from 25°C to 31°C, so it will be cooler than usual. It is cooler than 83% of similar days.
29°Cnear normal
usually 25°C–32°C
night: exceptionally warm
rain: more rain than usual
wind: exceptionally strong
28°Cnear normal
usually 25°C–32°C
night: warmer than usual
rain: exceptionally wet
wind: typical
25°Ccooler than usual
usually 25°C–32°C
cooler than 82% of similar days
night: exceptionally warm
rain: more rain than usual
wind: stronger than usual
25°Ccooler than usual
usually 25°C–31°C
cooler than 81% of similar days
night: warmer than usual
rain: more rain than usual
wind: stronger than usual
24°Ccooler than usual
usually 25°C–31°C
cooler than 83% of similar days
night: warmer than usual
rain: more rain than usual
wind: stronger than usual
25°Ccooler than usual
usually 25°C–31°C
cooler than 77% of similar days
night: exceptionally warm
rain: more rain than usual
wind: typical
How warm was this week in previous years?
Each bar shows the average daily high during the same 7-day period in each year.
cooler yearstypical rangewarmer years2026 forecastcurrent forecast
From 1981 to 2025, the 5-11 Sept period averaged 28°C by day. The coolest year was 1996 (22°C) and the warmest was 2008 (33°C). The current forecast averages 27°C - close to the historical median.
Historical reference: NASA POWER daily gridded data (MERRA-2), the 1991-2020 normal and a +/- 7-day calendar window. The typical range is the 20th-80th percentile. This is not a city weather-station reading and does not change the current forecast. NASA POWER Daily API.
Weather warnings - Sliven
No active weather warnings for Sliven (region: Sliven). The national weather service is not forecasting dangerous conditions.
14-day forecast - Sliven
Sliven 30 & 45-day weather - long-range outlook
Next 16 days · forecast
26°
around 19° at night · days with rain: 4
Weeks 3-4 · avg for September
25°
around 15° at night · rain chance 31%
Weeks 5-7 · avg for October
18°
around 9° at night · rain chance 39%
The 30 & 45-day outlook for Sliven: the next 16 days are a numerical forecast updated daily - on average 26° by day and 19° at night. Further out we rely on multi-year climate averages: around 25° in September, and about 18° in October. Forecasts beyond two weeks are indicative only.
Day-by-day forecast for Sliven
Saturday5 September 2026
☀️31°clear sky
Sunday6 September 2026
☀️29°clear sky
Monday7 September 2026
🌤️28°a few clouds
Tuesday8 September 2026
🌤️25°scattered clouds
Wednesday9 September 2026
☀️25°clear sky
Thursday10 September 2026
☀️24°clear sky
Friday11 September 2026
☀️25°clear sky
Saturday12 September 2026
☀️29°clear sky
Sunday13 September 2026
☁️30°overcast clouds
Monday14 September 2026
🌧️17°light rain
Tuesday15 September 2026
☀️23°clear sky
Wednesday16 September 2026
☁️23°overcast clouds
Thursday17 September 2026
☀️24°clear sky
Friday18 September 2026
☀️26°clear sky
Saturday19 September 2026
☀️27°clear sky
Sunday20 September 2026
☀️27°clear sky
UV index in Sliven - is it safe to sunbathe?
Today the UV index in Sliven is 6 (high) - unprotected fair skin can burn in about 30 minutes. SPF 30-50, a hat and sunglasses are a must. Better stay in shade between 11:00 and 15:00.
Pollen in Sliven - info for allergy sufferers
Today ragweed pollen is highest in Sliven - about 26 grains/m³, moderate level. Most allergy sufferers should not feel strong symptoms. Pollen levels are a CAMS model forecast and are indicative.
Sliven weather through the year
Warmest, driest months on average: April, May, June, July.
Upcoming public holidays in Bulgaria: Unification Day — 7 September · Independence Day — 22 September · Christmas Eve — 24 December.
Nearby and related places
FAQ - Sliven weather
What is the weather like in Sliven today?
Today it is about 31° during the day and 22° at night, clear sky.
How far ahead can I check the forecast for Sliven?
This page shows a detailed 14-day forecast plus the long-term monthly climate, so you can plan both a short trip and a holiday months ahead.