Siena weather in January

In January, Siena sees average daytime highs of 9°C and overnight lows near 2°C, with 55 mm of precipitation across 8.1 wet days and about 9.2 hours of daylight. It is the 12th-warmest and 9th-wettest month of the year here.

Day-to-day highs hold fairly steady near 9°C through the month. The sky is clear or mostly clear about 31% of the time in January, and the air most often feels dry.

Daylight stretches from about 8 h 48 min at the start of January to 9 h 36 min by month's end. Set against the rest of the year, January is Siena's 11th-clearest and 6th-windiest month. For the whole year in context, see Siena's year-round climate.

Daytime high: 9°; 12th warmest
Overnight low: 2°; 1st coldest
Precipitation: 55 mm; 8.1 wet days
Daylight: 9 h 06 min; 7:50 AM – 4:58 PM
Cloud cover: 60%; 11th clearest
Wind: 8 km/h; 6th windiest
Solar energy: 1.68 kWh/m²
Travel score: 1.9; out of 10

Air quality: Good; PM10 18.4 µg/m³ · 2019

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

← December Siena year-round climate February →Best places to visit in January

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Temperature in January

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 9°C through the month.

A typical January day in Siena reaches about 9°C in the afternoon and slips back to 2°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 5°C and 12°C. Set against its neighbours, January runs on par with December and about 1°C cooler than February.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Avg high (°C)	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9	9
Avg low (°C)	2	2	2	2	2	2	2	2	2	2	2	2	2	2	2	2	2	2	2	2	2	2	2	2	2	2	2	2	2	2	2

	Avg high (°C)	Avg low (°C)
1	9	2
2	9	2
3	9	2
4	9	2
5	9	2
6	9	2
7	9	2
8	9	2
9	9	2
10	9	2
11	9	2
12	9	2
13	9	2
14	9	2
15	9	2
16	9	2
17	9	2
18	9	2
19	9	2
20	9	2
21	9	2
22	9	2
23	9	2
24	9	2
25	9	2
26	9	2
27	9	2
28	9	2
29	9	2
30	9	2
31	9	2

How January really feels in Siena

Once humidity and wind are folded in, January averages 0 days that feel above 32°C and 31 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C

heat index over the day's high

Days feeling ≤ 0°C

wind chill below the day's low

The story in January is cold — wind chill drags the overnight "feels like" below the raw low.

Siena weather by month

How January compares with the rest of the year at a glance. January is the 12th-warmest and 9th-wettest month here — the current month is highlighted below.

Month	High / Low (°C)	Rainfall (mm)	Wet days	Snow days	Daylight (hours)	Travel score
Jan	9° / 2°	55	8.1	0.8	9.2	1.9
Feb	10° / 2°	65	8.4	1.2	10.2	2.5
Mar	14° / 4°	66	9	0.5	11.6	4.2
Apr	17° / 7°	79	11.3	0	13.2	5.4
May	22° / 11°	71	10.1	0	14.5	6.7
Jun	26° / 15°	50	7.5	0	15.1	7.4
Jul	29° / 17°	31	5	0	14.9	6.5
Aug	29° / 18°	40	6.2	0	13.8	6.3
Sep	25° / 14°	92	9	0	12.3	7.1
Oct	19° / 10°	109	10.4	0	10.8	6.2
Nov	14° / 6°	120	11.6	0.1	9.5	3.8
Dec	10° / 3°	79	10	0.5	8.8	2.1

Cloud cover in January

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 31% of the time in January.

Beyond those clear spells, partly cloudy skies cover about 13% of January, with mostly cloudy or overcast conditions the remaining 56%.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Clearer (%)	43	43	43	43	42	42	43	44	44	44	44	44	45	45	46	46	46	46	46	46	46	45	44	44	44	44	44	44	43	44	44
Cloudier (%)	57	57	57	57	58	58	57	56	56	56	56	56	55	55	54	54	54	54	54	54	54	55	56	56	56	56	56	56	57	56	56

	Clearer (%)	Cloudier (%)
1	43	57
2	43	57
3	43	57
4	43	57
5	42	58
6	42	58
7	43	57
8	44	56
9	44	56
10	44	56
11	44	56
12	44	56
13	45	55
14	45	55
15	46	54
16	46	54
17	46	54
18	46	54
19	46	54
20	46	54
21	46	54
22	45	55
23	44	56
24	44	56
25	44	56
26	44	56
27	44	56
28	44	56
29	43	57
30	44	56
31	44	56

Chance of precipitation in January

Any precipitationSnow

Siena gets around 55 mm of rain and snow over 8.1 wet days in January. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable precipitation averages around 26% and peaks near 29% on the wettest days, and about 1 day brings snow.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Rain chance (%)	29	28	28	27	26	25	25	24	24	24	24	24	24	24	25	25	26	26	26	27	27	27	27	28	28	28	28	28	28	28	29
Snow chance (%)	2	2	2	1	1	1	1	1	1	1	1	2	2	2	2	2	3	3	3	3	4	4	4	4	5	5	5	5	5	5	5

	Rain chance (%)	Snow chance (%)
1	29	2
2	28	2
3	28	2
4	27	1
5	26	1
6	25	1
7	25	1
8	24	1
9	24	1
10	24	1
11	24	1
12	24	2
13	24	2
14	24	2
15	25	2
16	25	2
17	26	3
18	26	3
19	26	3
20	27	3
21	27	4
22	27	4
23	27	4
24	28	4
25	28	5
26	28	5
27	28	5
28	28	5
29	28	5
30	28	5
31	29	5

Humidity in January

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, January lands in the dry band about 100% of days. It rarely turns muggy — the humid and sticky bands barely register.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Dry (%)	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100	100

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100
31	100

Wind in January

Winds average 8 km/h in January.

Across January, daily wind ranges from about 8 km/h on the calmest days to 9 km/h at its breeziest. It stays fairly steady from day to day.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Wind speed (km/h)	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	9	9	9	9	9	9	9
Feels	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm

	Wind speed (km/h)	Feels
1	8	calm
2	8	calm
3	8	calm
4	8	calm
5	8	calm
6	8	calm
7	8	calm
8	8	calm
9	8	calm
10	8	calm
11	8	calm
12	8	calm
13	8	calm
14	8	calm
15	8	calm
16	8	calm
17	8	calm
18	8	calm
19	8	calm
20	8	calm
21	8	calm
22	8	calm
23	8	calm
24	8	calm
25	9	calm
26	9	calm
27	9	calm
28	9	calm
29	9	calm
30	9	calm
31	9	calm

Sunrise & sunset in January

DaylightNight

Daylight runs from about 8 h 48 min at the start of January to 9 h 36 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 48 minutes over January. Sunrise moves from 7:53 AM to 7:40 AM, and sunset from 4:43 PM to 5:16 PM.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Daylight (h)	8.8	8.9	8.9	8.9	8.9	8.9	8.9	8.9	9.0	9.0	9.0	9.0	9.0	9.1	9.1	9.1	9.2	9.2	9.2	9.2	9.3	9.3	9.3	9.4	9.4	9.4	9.5	9.5	9.5	9.6	9.6
Sunrise (AM)	7:53	7:53	7:53	7:53	7:53	7:53	7:53	7:53	7:52	7:52	7:52	7:52	7:51	7:51	7:51	7:50	7:50	7:49	7:49	7:48	7:48	7:47	7:46	7:46	7:45	7:44	7:43	7:43	7:42	7:41	7:40
Sunset (PM)	4:43	4:44	4:45	4:45	4:46	4:47	4:48	4:49	4:50	4:51	4:52	4:53	4:54	4:55	4:57	4:58	4:59	5:00	5:01	5:02	5:04	5:05	5:06	5:07	5:09	5:10	5:11	5:12	5:14	5:15	5:16

	Daylight (h)	Sunrise (AM)	Sunset (PM)
1	8.8	7:53	4:43
2	8.9	7:53	4:44
3	8.9	7:53	4:45
4	8.9	7:53	4:45
5	8.9	7:53	4:46
6	8.9	7:53	4:47
7	8.9	7:53	4:48
8	8.9	7:53	4:49
9	9.0	7:52	4:50
10	9.0	7:52	4:51
11	9.0	7:52	4:52
12	9.0	7:52	4:53
13	9.0	7:51	4:54
14	9.1	7:51	4:55
15	9.1	7:51	4:57
16	9.1	7:50	4:58
17	9.2	7:50	4:59
18	9.2	7:49	5:00
19	9.2	7:49	5:01
20	9.2	7:48	5:02
21	9.3	7:48	5:04
22	9.3	7:47	5:05
23	9.3	7:46	5:06
24	9.4	7:46	5:07
25	9.4	7:45	5:09
26	9.4	7:44	5:10
27	9.5	7:43	5:11
28	9.5	7:43	5:12
29	9.5	7:42	5:14
30	9.6	7:41	5:15
31	9.6	7:40	5:16

Solar energy in January

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in January, about 1.68 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 — January's 1.68 kWh/m² sits near the bottom.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30	31
Solar energy (kWh/m²)	1.5	1.5	1.5	1.5	1.5	1.5	1.5	1.5	1.6	1.6	1.6	1.6	1.6	1.6	1.6	1.7	1.7	1.7	1.7	1.8	1.8	1.8	1.8	1.8	1.9	1.9	1.9	1.9	2.0	2.0	2.0
Level	Dim	Dim	Dim	Dim	Dim	Dim	Dim	Dim	Dim	Dim	Dim	Dim	Dim	Dim	Dim	Dim	Dim	Dim	Dim	Dim	Dim	Dim	Dim	Dim	Dim	Dim	Dim	Dim	Dim	Moderate	Moderate

	Solar energy (kWh/m²)	Level
1	1.5	Dim
2	1.5	Dim
3	1.5	Dim
4	1.5	Dim
5	1.5	Dim
6	1.5	Dim
7	1.5	Dim
8	1.5	Dim
9	1.6	Dim
10	1.6	Dim
11	1.6	Dim
12	1.6	Dim
13	1.6	Dim
14	1.6	Dim
15	1.6	Dim
16	1.7	Dim
17	1.7	Dim
18	1.7	Dim
19	1.7	Dim
20	1.8	Dim
21	1.8	Dim
22	1.8	Dim
23	1.8	Dim
24	1.8	Dim
25	1.9	Dim
26	1.9	Dim
27	1.9	Dim
28	1.9	Dim
29	2.0	Dim
30	2.0	Moderate
31	2.0	Moderate

Planning a trip in January

Is January a good time to visit Siena?

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

1.9

Sightseeing

12th-best month of the year

0.0

Beach & pool

10th-best month of the year

January is a weaker month for outdoor sightseeing in Siena.

What to pack for Siena in January

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

In January, Siena sees daytime highs around 9°C and nights near 2°C. Pack a warm layer. Worth having: rain gear. About 8 days see rain.

a warm layerrain gear

UV index in Siena in January

LowModerateHighVery highExtreme

Clear-sky midday UV in January peaks around 1. 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.

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
UV index (midday)	1	3	5	6	6	8	9	7	5	3	2	1
Level	Low	Moderate	Moderate	High	High	Very high	Very high	Very high	High	Moderate	Moderate	Low

	UV index (midday)	Level
Jan	1	Low
Feb	3	Moderate
Mar	5	Moderate
Apr	6	High
May	6	High
Jun	8	Very high
Jul	9	Very high
Aug	7	Very high
Sep	5	High
Oct	3	Moderate
Nov	2	Moderate
Dec	1	Low

Air quality in Siena in January

GoodModeratePoorUnhealthyVery unhealthy

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

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
PM2.5 (µg/m³)	14	14	17	16	15	14	12	13	12	13	12	12
Level	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Good	Moderate	Moderate	Moderate	Good	Moderate

	PM2.5 (µg/m³)	Level
Jan	14	Moderate
Feb	14	Moderate
Mar	17	Moderate
Apr	16	Moderate
May	15	Moderate
Jun	14	Moderate
Jul	12	Good
Aug	13	Moderate
Sep	12	Moderate
Oct	13	Moderate
Nov	12	Good
Dec	12	Moderate

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

trees 57%

16 km

520 m

trees 55%

80 km

1,724 m

trees 62%

treesshrubsgrasslandcroplandartificial surfaceswater

← December Siena year-round climate February →Best places to visit in January

January 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

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).

	Avg high (°C)	Avg low (°C)
1	9	2
2	9	2
3	9	2
4	9	2
5	9	2
6	9	2
7	9	2
8	9	2
9	9	2
10	9	2
11	9	2
12	9	2
13	9	2
14	9	2
15	9	2
16	9	2
17	9	2
18	9	2
19	9	2
20	9	2
21	9	2
22	9	2
23	9	2
24	9	2
25	9	2
26	9	2
27	9	2
28	9	2
29	9	2
30	9	2
31	9	2

	Clearer (%)	Cloudier (%)
1	43	57
2	43	57
3	43	57
4	43	57
5	42	58
6	42	58
7	43	57
8	44	56
9	44	56
10	44	56
11	44	56
12	44	56
13	45	55
14	45	55
15	46	54
16	46	54
17	46	54
18	46	54
19	46	54
20	46	54
21	46	54
22	45	55
23	44	56
24	44	56
25	44	56
26	44	56
27	44	56
28	44	56
29	43	57
30	44	56
31	44	56

	Rain chance (%)	Snow chance (%)
1	29	2
2	28	2
3	28	2
4	27	1
5	26	1
6	25	1
7	25	1
8	24	1
9	24	1
10	24	1
11	24	1
12	24	2
13	24	2
14	24	2
15	25	2
16	25	2
17	26	3
18	26	3
19	26	3
20	27	3
21	27	4
22	27	4
23	27	4
24	28	4
25	28	5
26	28	5
27	28	5
28	28	5
29	28	5
30	28	5
31	29	5

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100
31	100

	Avg high (°C)	Avg low (°C)
1	9	2
2	9	2
3	9	2
4	9	2
5	9	2
6	9	2
7	9	2
8	9	2
9	9	2
10	9	2
11	9	2
12	9	2
13	9	2
14	9	2
15	9	2
16	9	2
17	9	2
18	9	2
19	9	2
20	9	2
21	9	2
22	9	2
23	9	2
24	9	2
25	9	2
26	9	2
27	9	2
28	9	2
29	9	2
30	9	2
31	9	2

	Clearer (%)	Cloudier (%)
1	43	57
2	43	57
3	43	57
4	43	57
5	42	58
6	42	58
7	43	57
8	44	56
9	44	56
10	44	56
11	44	56
12	44	56
13	45	55
14	45	55
15	46	54
16	46	54
17	46	54
18	46	54
19	46	54
20	46	54
21	46	54
22	45	55
23	44	56
24	44	56
25	44	56
26	44	56
27	44	56
28	44	56
29	43	57
30	44	56
31	44	56

	Rain chance (%)	Snow chance (%)
1	29	2
2	28	2
3	28	2
4	27	1
5	26	1
6	25	1
7	25	1
8	24	1
9	24	1
10	24	1
11	24	1
12	24	2
13	24	2
14	24	2
15	25	2
16	25	2
17	26	3
18	26	3
19	26	3
20	27	3
21	27	4
22	27	4
23	27	4
24	28	4
25	28	5
26	28	5
27	28	5
28	28	5
29	28	5
30	28	5
31	29	5

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100
31	100

	Avg high (°C)	Avg low (°C)
1	9	2
2	9	2
3	9	2
4	9	2
5	9	2
6	9	2
7	9	2
8	9	2
9	9	2
10	9	2
11	9	2
12	9	2
13	9	2
14	9	2
15	9	2
16	9	2
17	9	2
18	9	2
19	9	2
20	9	2
21	9	2
22	9	2
23	9	2
24	9	2
25	9	2
26	9	2
27	9	2
28	9	2
29	9	2
30	9	2
31	9	2

	Clearer (%)	Cloudier (%)
1	43	57
2	43	57
3	43	57
4	43	57
5	42	58
6	42	58
7	43	57
8	44	56
9	44	56
10	44	56
11	44	56
12	44	56
13	45	55
14	45	55
15	46	54
16	46	54
17	46	54
18	46	54
19	46	54
20	46	54
21	46	54
22	45	55
23	44	56
24	44	56
25	44	56
26	44	56
27	44	56
28	44	56
29	43	57
30	44	56
31	44	56

	Rain chance (%)	Snow chance (%)
1	29	2
2	28	2
3	28	2
4	27	1
5	26	1
6	25	1
7	25	1
8	24	1
9	24	1
10	24	1
11	24	1
12	24	2
13	24	2
14	24	2
15	25	2
16	25	2
17	26	3
18	26	3
19	26	3
20	27	3
21	27	4
22	27	4
23	27	4
24	28	4
25	28	5
26	28	5
27	28	5
28	28	5
29	28	5
30	28	5
31	29	5

	Dry (%)
1	100
2	100
3	100
4	100
5	100
6	100
7	100
8	100
9	100
10	100
11	100
12	100
13	100
14	100
15	100
16	100
17	100
18	100
19	100
20	100
21	100
22	100
23	100
24	100
25	100
26	100
27	100
28	100
29	100
30	100
31	100