Sliven weather in May

In May, Sliven sees average daytime highs of 20°C and overnight lows near 10°C, with 106 mm of rain across 14.5 wet days and about 14.4 hours of daylight. It is the 5th-warmest and 1st-wettest month of the year here.

Highs climb over the month, from about 18°C in the first days to 22°C by the end. The sky is clear or mostly clear about 27% of the time in May, and the air most often feels dry.

Daylight stretches from about 13 h 48 min at the start of May to 14 h 54 min by month's end. Set against the rest of the year, May is Sliven's 6th-clearest and 7th-windiest month. For the whole year in context, see Sliven's year-round climate.

Daytime high
20°
5th warmest
Overnight low
10°
8th coldest
Rainfall
106 mm
14.5 wet days
Daylight
14 h 24 min
4:58 AM – 7:24 PM
Cloud cover
59%
6th clearest
Wind
8 km/h
7th windiest
Solar energy
5.9 kWh/m²
Travel score
5.7
out of 10

Sliven is city in Sliven municipality, Sliven oblast, Bulgaria.

Air quality
Good
PM10 17.8 µg/m³ · 2019
Density
432/km²
people per km²

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 18°C in the first days to 22°C by the end.

A typical May day in Sliven reaches about 20°C in the afternoon and slips back to 10°C overnight — a 10°C spread between the day's warmth and the night's chill. On most days the high lands between 15°C and 25°C. Set against its neighbours, May runs about 5°C warmer than April and about 4°C cooler than June.

10°20°30°151015202531
Avg high (°C)Avg low (°C)
1188
2188
3189
4189
5199
6199
7199
8199
9199
101910
112010
122010
132010
142010
152010
162011
172011
182011
192011
202111
212111
222111
232111
242112
252112
262112
272112
282112
292212
302212
312212

How May really feels in Sliven

Once humidity and wind are folded in, May averages 0 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
0
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

May 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 May compares with the rest of the year at a glance. May is the 5th-warmest and 1st-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -3°537.75.19.20.0
Feb / -2°5485.110.30.3
Mar10° / 6710.74.311.62.0
Apr15° / 7512.30.913.14.2
May20° / 10°10614.5014.45.7
Jun24° / 14°10014015.16.3
Jul27° / 16°8911.7014.86.7
Aug27° / 16°568013.77.2
Sep22° / 12°587.8012.37.3
Oct16° / 637.80.410.85.4
Nov10° / 587.42.19.62.3
Dec / -1°638.64.58.90.1

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 27% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 22% of May, with mostly cloudy or overcast conditions the remaining 51%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14852
24852
34852
44753
54852
64753
74852
84753
94951
104852
114951
124951
134951
144852
154951
164951
174951
184951
194951
204951
214951
224951
234951
244951
254951
265050
275149
285149
295149
305248
315248

Chance of precipitation in May

Any precipitation

Sliven gets around 106 mm of rain over 14.5 wet days in May, the wettest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 47% and peaks near 53% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%151015202531
Rain chance (%)
142
243
343
444
544
644
745
845
945
1045
1146
1246
1346
1446
1547
1647
1747
1848
1948
2048
2149
2249
2350
2450
2551
2651
2752
2852
2952
3052
3153

Humidity in May

DryComfortableHumidMuggyOppressiveMiserable

Most of May feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, May lands in the dry band about 78% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)
19820
29730
39640
49640
59550
69460
79280
89190
990100
1088120
1187130
1286140
1384160
1482171
1580191
1679201
1778211
1876231
1974242
2073252
2172262
2269283
2368293
2467303
2565314
2664324
2761345
2860355
2958366
3056386
3153407

Wind in May

Winds average 8 km/h in May.

Across May, daily wind ranges from about 7 km/h on the calmest days to 8 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (km/h)Feels
18calm
28calm
38calm
48calm
58calm
68calm
78calm
88calm
98calm
108calm
118calm
128calm
137calm
147calm
157calm
167calm
177calm
187calm
197calm
207calm
217calm
227calm
237calm
247calm
257calm
267calm
277calm
287calm
297calm
307calm
317calm

Sunrise & sunset in May

DaylightNight

Daylight runs from about 13 h 48 min at the start of May to 14 h 54 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 66 minutes over May. Sunrise moves from 5:17 AM to 4:46 AM, and sunset from 7:07 PM to 7:38 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
113.85:177:07
213.95:157:08
313.95:147:09
414.05:137:11
514.05:117:12
614.05:107:13
714.15:097:14
814.15:077:15
914.25:067:16
1014.25:057:17
1114.25:047:18
1214.35:027:19
1314.35:017:21
1414.45:007:22
1514.44:597:23
1614.44:587:24
1714.54:577:25
1814.54:567:26
1914.54:557:27
2014.64:547:28
2114.64:537:29
2214.64:527:30
2314.74:527:31
2414.74:517:32
2514.74:507:33
2614.74:497:34
2714.84:487:35
2814.84:487:36
2914.84:477:37
3014.84:477:37
3114.94:467:38

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.9 kWh/m².

For context, solar energy here swings from a low near 1.43 kWh/m² to a high of 6.45 kWh/m² in June across the year — May's 5.9 kWh/m² sits near the top of that range.

0246151015202531
Solar energy (kWh/m²)Level
15.7Bright
25.7Bright
35.7Bright
45.7Bright
55.8Bright
65.8Bright
75.8Bright
85.8Bright
95.8Bright
105.8Bright
115.8Bright
125.9Bright
135.9Bright
145.9Bright
155.9Bright
165.9Bright
175.9Bright
185.9Bright
195.9Bright
206.0Bright
216.0Bright
226.0Bright
236.0Bright
246.0Bright
256.0Intense
266.0Intense
276.0Intense
286.0Intense
296.1Intense
306.1Intense
316.1Intense
Planning a trip in May

Is May a good time to visit Sliven?

Our two travel scores rate May for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

5.7
Sightseeing
5th-best month of the year
2.9
Beach & pool
5th-best month of the year

May is a reasonable time to visit Sliven for sightseeing.

What to pack for Sliven in May

From May's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In May, Sliven sees daytime highs around 20°C and nights near 10°C. Pack rain gear. Worth having: sun protection. About 15 days see rain.

rain gearsun protection

UV index in Sliven in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May peaks around 6 — enough to warrant sun protection. 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.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighModerateLowJul 17UV 9Dec 21UV 1
UV index (midday)Level
Jan1Low
Feb2Moderate
Mar3Moderate
Apr8Very high
May6High
Jun8Very high
Jul9Very high
Aug8Very high
Sep6High
Oct4Moderate
Nov2Low
Dec1Low

Air quality in Sliven in May

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where May 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).

01020JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodMar 1916 µg/m³Sep 1910 µg/m³
PM2.5 (µg/m³)Level
Jan13Moderate
Feb14Moderate
Mar16Moderate
Apr15Moderate
May13Moderate
Jun13Moderate
Jul12Good
Aug11Good
Sep10Good
Oct10Good
Nov11Good
Dec11Good
Location & terrain

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.

Nova ZagoraKarnobatStara ZagoraTargovishteGorna OryahovitsaVeliko TarnovoPopovo

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.

3 km
598 m
16 km
1,041 m
80 km
1,510 m
treesgrasslandcroplandartificial surfaceswater
May weather nearby: Yambol 27 km · Nova Zagora 34 km · Karnobat 54 km · Stara Zagora 63 km · Targovishte 66 km · Gorna Oryahovitsa 71 km · Veliko Tarnovo 72 km · Popovo 74 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
Christian 65%Muslim 10%none 5%other 0%

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. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).