Siena weather in October

In October, Siena sees average daytime highs of 19°C and overnight lows near 10°C, with 109 mm of rain across 10.4 wet days and about 10.8 hours of daylight. It is the 6th-warmest and 2nd-wettest month of the year here.

Highs ease over the month, from about 21°C in the first days to 17°C by the end. The sky is clear or mostly clear about 36% of the time in October, and the air most often feels dry.

Daylight stretches from about 11 h 30 min at the start of October to 10 h 06 min by month's end. Set against the rest of the year, October is Siena's 8th-clearest and 7th-windiest month. For the whole year in context, see Siena's year-round climate.

Daytime high
19°
6th warmest
Overnight low
10°
7th coldest
Rainfall
109 mm
10.4 wet days
Daylight
10 h 48 min
6:36 AM – 5:23 PM
Cloud cover
55%
8th clearest
Wind
8 km/h
7th windiest
Solar energy
2.85 kWh/m²
Travel score
6.2
out of 10
Air quality
Good
PM10 18.4 µg/m³ · 2019

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

Temperature in October

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 21°C in the first days to 17°C by the end.

A typical October day in Siena reaches about 19°C in the afternoon and slips back to 10°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 16°C and 23°C. Set against its neighbours, October runs about 5°C cooler than September and about 6°C warmer than November.

10°20°30°151015202531
Avg high (°C)Avg low (°C)
12212
22212
32112
42112
52112
62112
72112
82111
92011
102011
112011
122011
132011
142011
151911
161910
171910
181910
191910
201910
211810
221810
231810
241810
25189
26189
27189
28179
29179
30179
31179

How October really feels in Siena

Once humidity and wind are folded in, October 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

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

Siena weather by month

How October compares with the rest of the year at a glance. October is the 6th-warmest and 2nd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / 558.10.89.21.9
Feb10° / 658.41.210.22.5
Mar14° / 6690.511.64.2
Apr17° / 7911.3013.25.4
May22° / 11°7110.1014.56.7
Jun26° / 15°507.5015.17.4
Jul29° / 17°315014.96.5
Aug29° / 18°406.2013.86.3
Sep25° / 14°929012.37.1
Oct19° / 10°10910.4010.86.2
Nov14° / 12011.60.19.53.8
Dec10° / 79100.58.82.1

Cloud cover in October

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 36% of the time in October.

Beyond those clear spells, partly cloudy skies cover about 19% of October, with mostly cloudy or overcast conditions the remaining 45%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
15941
25941
35941
45842
55842
65743
75644
85644
95644
105644
115644
125644
135545
145644
155644
165545
175644
185644
195644
205545
215644
225644
235545
245545
255347
265347
275248
285248
295050
305050
314852

Chance of precipitation in October

Any precipitation

Siena gets around 109 mm of rain over 10.4 wet days in October. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 33% and peaks near 36% on the wettest days.

0%10%20%30%40%50%151015202531
Rain chance (%)
135
235
335
435
536
636
736
835
935
1035
1134
1234
1334
1433
1533
1632
1732
1832
1931
2031
2131
2231
2331
2431
2531
2631
2732
2832
2933
3033
3134

Humidity in October

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, October lands in the dry band about 67% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202531
Dry (%)Comfortable (%)Humid (%)Muggy (%)
15232151
25331151
35431141
45431141
55630131
65630131
75829121
86028120
96227110
106326110
116525100
126624100
13672490
14682390
15702280
16702280
17702280
18702280
19712270
20712270
21712270
22712270
23722260
24722260
25722260
26732250
27732250
28732250
29752140
30752140
31772030

Wind in October

Winds average 8 km/h in October.

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

051015151015202531
Wind speed (km/h)Feels
18calm
28calm
38calm
48calm
58calm
68calm
78calm
88calm
98calm
108calm
118calm
128calm
138calm
148calm
158calm
168calm
178calm
188calm
198calm
208calm
218calm
228calm
238calm
248calm
258calm
268calm
278calm
288calm
298calm
308calm
318calm

Sunrise & sunset in October

DaylightNight

Daylight runs from about 11 h 30 min at the start of October to 10 h 06 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 84 minutes over October. Sunrise moves from 6:18 AM to 6:55 AM, and sunset from 5:50 PM to 5:01 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
111.56:185:50
211.56:195:48
311.46:205:46
411.46:215:44
511.36:225:42
611.36:245:41
711.26:255:39
811.26:265:37
911.16:275:35
1011.16:295:34
1111.06:305:32
1211.06:315:30
1310.96:325:28
1410.96:345:27
1510.86:355:25
1610.86:365:23
1710.76:375:22
1810.76:395:20
1910.66:405:19
2010.66:415:17
2110.66:425:15
2210.56:445:14
2310.56:455:12
2410.46:465:11
2510.46:485:09
2610.36:495:08
2710.36:505:07
2810.26:515:05
2910.26:535:04
3010.16:545:02
3110.16:555:01

Solar energy in October

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in October, about 2.85 kWh/m².

For context, solar energy here swings from a low near 1.43 kWh/m² to a high of 6.97 kWh/m² in July across the year — October's 2.85 kWh/m² falls in the middle.

01234151015202531
Solar energy (kWh/m²)Level
13.5Moderate
23.5Moderate
33.4Moderate
43.4Moderate
53.3Moderate
63.3Moderate
73.2Moderate
83.2Moderate
93.1Moderate
103.1Moderate
113.1Moderate
123.0Moderate
133.0Moderate
143.0Moderate
152.9Moderate
162.9Moderate
172.8Moderate
182.8Moderate
192.7Moderate
202.7Moderate
212.7Moderate
222.6Moderate
232.6Moderate
242.5Moderate
252.5Moderate
262.5Moderate
272.4Moderate
282.4Moderate
292.3Moderate
302.3Moderate
312.3Moderate
Planning a trip in October

Is October a good time to visit Siena?

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

6.2
Sightseeing
6th-best month of the year
2.8
Beach & pool
6th-best month of the year

October is a reasonable time to visit Siena for sightseeing.

What to pack for Siena in October

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

In October, Siena sees daytime highs around 19°C and nights near 10°C. Worth packing: rain gear. About 10 days see rain.

rain gear

UV index in Siena in October

LowModerateHighVery highExtreme

Clear-sky midday UV in October peaks around 3 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Siena peaks around July 14 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 23 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 14UV 9Dec 23UV 1
UV index (midday)Level
Jan1Low
Feb3Moderate
Mar5Moderate
Apr6High
May6High
Jun8Very high
Jul9Very high
Aug7Very high
Sep5High
Oct3Moderate
Nov2Moderate
Dec1Low

Air quality in Siena in October

GoodModeratePoorUnhealthyVery unhealthy

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

Air quality in Siena is worst in March — around 17 µg/m³ PM2.5 (moderate), and holds fairly steady the rest of the year.

Modeled monthly averages (CAMS reanalysis, 2015–2024).

01020JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodModerateMar 2016 µg/m³Nov 1712 µg/m³
PM2.5 (µg/m³)Level
Jan14Moderate
Feb14Moderate
Mar17Moderate
Apr16Moderate
May15Moderate
Jun14Moderate
Jul12Good
Aug13Moderate
Sep12Moderate
Oct13Moderate
Nov12Good
Dec12Moderate
Location & terrain

Where is Siena?

Siena sits at 43.3°N, 11.3°E, 322 m above sea level, in Italy. The nearest listed city is Colle di Val d'Elsa, 20 km away.

Topography around Siena

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

Within 3 km, the terrain around Siena has only modest variations in elevation — a maximum elevation change of 199 m around an average of 283 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 520 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,724 m.

The land around Siena is covered by trees (57%) and grassland (22%) within 3 km, trees (55%) and cropland (24%) within 16 km, and trees (62%) within 80 km.

3 km
199 m
16 km
520 m
80 km
1,724 m
treesshrubsgrasslandcroplandartificial surfaceswater
October weather nearby: Colle di Val d'Elsa 20 km · Poggibonsi 22 km · Montevarchi 30 km · San Giovanni Valdarno 32 km · Arezzo 47 km · Scandicci 50 km · Campo di Marte 51 km · Florence 52 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 Siena (43.3182°, 11.3306°, elevation 322 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).