Bologna weather in September

In September, Bologna sees average daytime highs of 25°C and overnight lows near 16°C, with 68 mm of rain across 8 wet days and about 12.3 hours of daylight. It is the 4th-warmest and 6th-wettest month of the year here.

Highs ease over the month, from about 28°C in the first days to 23°C by the end. The sky is clear or mostly clear about 49% of the time in September, and the air most often feels dry.

Daylight stretches from about 13 h 06 min at the start of September to 11 h 36 min by month's end. Set against the rest of the year, September is Bologna's 3rd-clearest and 7th-windiest month. For the whole year in context, see Bologna's year-round climate.

Daytime high
25°
4th warmest
Overnight low
16°
9th coldest
Rainfall
68 mm
8 wet days
Daylight
12 h 18 min
6:00 AM – 6:18 PM
Cloud cover
44%
3rd clearest
Wind
7 km/h
7th windiest
Solar energy
4.2 kWh/m²
Travel score
7.2
out of 10
Air quality
Moderate
PM2.5 15 µg/m³ · 2019

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

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 28°C in the first days to 23°C by the end.

A typical September day in Bologna reaches about 25°C in the afternoon and slips back to 16°C overnight — a 10°C spread between the day's warmth and the night's chill. On most days the high lands between 21°C and 30°C. Set against its neighbours, September runs about 5°C cooler than August and about 6°C warmer than October.

10°15°20°25°30°35°151015202530
Avg high (°C)Avg low (°C)
12818
22818
32817
42817
52717
62717
72717
82717
92716
102616
112616
122616
132616
142616
152516
162515
172515
182515
192515
202415
212415
222415
232415
242414
252414
262314
272314
282314
292314
302314

How September really feels in Bologna

Once humidity and wind are folded in, September 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

September sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Bologna weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 6th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / 457.4291.4
Feb10° / 647.52.110.12.4
Mar15° / 638.1111.64.7
Apr18° / 7610.20.213.25.9
May23° / 13°769.5014.66.9
Jun28° / 18°607.8015.36.4
Jul31° / 20°466.30155.2
Aug30° / 20°537.7013.95.3
Sep25° / 16°688012.37.2
Oct19° / 11°768.8010.76.3
Nov13° / 91100.59.43.6
Dec / 698.71.68.71.6

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 49% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 19% of September, with mostly cloudy or overcast conditions the remaining 31%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
17525
27525
37525
47525
57525
67525
77426
87426
97327
107327
117228
127129
137129
147030
156931
166832
176733
186634
196634
206535
216535
226436
236436
246436
256337
266337
276238
286238
296139
306139

Chance of precipitation in September

Any precipitation

Bologna gets around 68 mm of rain over 8 wet days in September. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 27% and peaks near 29% on the wettest days.

0%10%20%30%40%151015202530
Rain chance (%)
129
229
329
428
528
628
728
828
928
1027
1127
1227
1327
1427
1527
1627
1727
1827
1927
2027
2126
2226
2326
2426
2526
2626
2726
2827
2927
3028

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the dry band about 39% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)
124323411
225323310
32633339
42733327
52834326
62934325
73034325
83134314
93134314
103234313
113334303
123433303
133533293
143633293
153732283
163832273
174032263
184132243
194331233
204431223
214631213
224731203
234831192
244931182
255031172
265032162
275232151
285233141
295234131
305334121

Wind in September

Winds average 7 km/h in September.

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

0246810151015202530
Wind speed (km/h)Feels
17calm
27calm
37calm
47calm
57calm
67calm
77calm
87calm
97calm
107calm
117calm
127calm
137calm
147calm
157calm
167calm
177calm
187calm
197calm
207calm
217calm
227calm
237calm
247calm
257calm
267calm
277calm
287calm
297calm
307calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 h 06 min at the start of September to 11 h 36 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 90 minutes over September. Sunrise moves from 5:42 AM to 6:17 AM, and sunset from 6:47 PM to 5:51 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.15:426:47
213.05:436:45
313.05:446:43
412.95:456:41
512.95:476:39
612.85:486:37
712.85:496:36
812.75:506:34
912.75:516:32
1012.65:536:30
1112.65:546:28
1212.55:556:26
1312.55:566:24
1412.45:576:22
1512.45:596:20
1612.36:006:18
1712.36:016:16
1812.26:026:14
1912.16:036:12
2012.16:056:10
2112.06:066:08
2212.06:076:06
2311.96:086:04
2411.96:106:02
2511.86:116:01
2611.86:125:59
2711.76:135:57
2811.76:155:55
2911.66:165:53
3011.66:175:51

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.2 kWh/m².

For context, solar energy here swings from a low near 1.27 kWh/m² to a high of 6.68 kWh/m² in July across the year — September's 4.2 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
15.0Bright
24.9Bright
34.8Bright
44.8Bright
54.8Bright
64.7Bright
74.6Bright
84.6Bright
94.5Bright
104.5Bright
114.4Bright
124.4Bright
134.3Bright
144.3Bright
154.2Bright
164.1Bright
174.1Bright
184.0Bright
194.0Moderate
203.9Moderate
213.9Moderate
223.8Moderate
233.8Moderate
243.7Moderate
253.7Moderate
263.6Moderate
273.6Moderate
283.5Moderate
293.5Moderate
303.4Moderate
Planning a trip in September

Is September a good time to visit Bologna?

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

7.2
Sightseeing
1st-best month of the year
6.6
Beach & pool
4th-best month of the year

September is one of the better times to visit Bologna for general sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Bologna in September

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

In September, Bologna sees daytime highs around 25°C and nights near 16°C. Worth packing: light clothes and rain gear. About 8 days see rain.

light clothesrain gear

UV index in Bologna in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 5 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Bologna peaks around July 13 at about 8 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near January 1 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 13UV 8Jan 1UV 1
UV index (midday)Level
Jan1Low
Feb3Moderate
Mar5Moderate
Apr7High
May6High
Jun8Very high
Jul9Very high
Aug7Very high
Sep5Moderate
Oct3Moderate
Nov2Low
Dec1Low

Air quality in Bologna in September

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where September falls, not just the annual average.

Air quality in Bologna is worst in March — around 18 µg/m³ PM2.5 (moderate), and holds fairly steady the rest of the year.

Seasonal pattern from CAMS reanalysis, scaled to Bologna's WHO annual average of 15 µg/m³.

01020JanFebMarAprMayJunJulAugSepOctNovDecModerateMar 1918 µg/m³Sep 1213 µg/m³
PM2.5 (µg/m³)Level
Jan17Moderate
Feb16Moderate
Mar18Moderate
Apr17Moderate
May16Moderate
Jun15Moderate
Jul13Moderate
Aug13Moderate
Sep13Moderate
Oct14Moderate
Nov14Moderate
Dec15Moderate
Location & terrain

Where is Bologna?

Bologna sits at 44.5°N, 11.3°E, 54 m above sea level, in Italy. The nearest listed city is Casalecchio di Reno, 5.0 km away.

Topography around Bologna

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Bologna.

Within 3 km, the terrain around Bologna has significant variations in elevation — a maximum elevation change of 264 m around an average of 85 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 532 m; within 80 km, very significant variations in elevation — a maximum elevation change of 2,113 m.

The land around Bologna is covered by artificial surfaces (54%) and trees (38%) within 3 km, cropland (37%) and trees (30%) within 16 km, and cropland (39%) and trees (36%) within 80 km.

3 km
264 m
16 km
532 m
80 km
2,113 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Casalecchio di Reno 5.0 km · San Lazzaro 6.0 km · Castel Maggiore 9.0 km · Zola Predosa 10 km · San Giovanni in Persiceto 20 km · Castelfranco Emilia 25 km · Vignola 26 km · Cento 27 km

Italy travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type C / F / L
230 V · 50 Hz
Prices
≈ 69% of US
price level, 2025
GDP per capita
$43,309
2025
Happiness
6.6 / 10
World Happiness, 2025
Safe drinking water
97%
of population, 2024
Homicide rate
0.6
per 100k, 2023
Road deaths
5.3
per 100k/yr, 2019
Income group
High
World Bank
English
Moderate
EF EPI 513
Religion
Christian 81%unaffiliated 13%Muslim 5%other 1%

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 Bologna (44.4938°, 11.3387°, elevation 54 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).