Terni weather in September

In September, Terni sees average daytime highs of 23°C and overnight lows near 13°C, with 82 mm of rain across 9.4 wet days and about 12.3 hours of daylight. It is the 4th-warmest and 7th-wettest month of the year here.

Highs ease over the month, from about 26°C in the first days to 21°C by the end. The sky is clear or mostly clear about 48% of the time in September, and the air most often feels dry.

Daylight stretches from about 13 hours at the start of September to 11 h 36 min by month's end. Set against the rest of the year, September is Terni's 4th-clearest and 7th-windiest month. For the whole year in context, see Terni's year-round climate.

Daytime high: 23°; 4th warmest
Overnight low: 13°; 9th coldest
Rainfall: 82 mm; 9.4 wet days
Daylight: 12 h 18 min; 5:55 AM – 6:12 PM
Cloud cover: 45%; 4th clearest
Wind: 6 km/h; 7th windiest
Solar energy: 4.45 kWh/m²
Travel score: 7.1; out of 10

Air quality: Elevated; PM2.5 17.3 µg/m³ · 2019

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

← August Terni year-round climate October →Best places to visit in September

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

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 26°C in the first days to 21°C by the end.

A typical September day in Terni reaches about 23°C in the afternoon and slips back to 13°C overnight — a 10°C spread between the day's warmth and the night's chill. On most days the high lands between 19°C and 27°C. Set against its neighbours, September runs about 5°C cooler than August and about 5°C warmer than October.

	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
Avg high (°C)	26	26	26	25	25	25	25	25	24	24	24	24	24	24	23	23	23	23	23	22	22	22	22	22	22	21	21	21	21	21
Avg low (°C)	15	15	15	15	14	14	14	14	14	14	14	14	13	13	13	13	13	13	13	13	13	12	12	12	12	12	12	12	12	11

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

How September really feels in Terni

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

heat index over the day's high

Days feeling ≤ 0°C

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.

Terni weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 7th-wettest month here — the current month is highlighted below.

Month	High / Low (°C)	Rainfall (mm)	Wet days	Snow days	Daylight (hours)	Travel score
Jan	8° / 1°	71	9.5	3	9.2	1.3
Feb	9° / 1°	81	10	3.4	10.3	1.8
Mar	12° / 3°	92	10.9	3	11.6	3.4
Apr	16° / 6°	98	13	0.9	13.1	4.5
May	20° / 10°	83	11.4	0.1	14.4	6.2
Jun	25° / 14°	53	8.8	0	15.1	7.3
Jul	28° / 17°	30	5.7	0	14.8	7.2
Aug	28° / 17°	33	6.1	0	13.7	6.8
Sep	23° / 13°	82	9.4	0	12.3	7.1
Oct	18° / 10°	105	10.5	0.1	10.8	5.9
Nov	13° / 6°	129	12.4	1	9.6	3.4
Dec	9° / 2°	107	10.7	2.8	8.9	1.6

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 48% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 18% of September, with mostly cloudy or overcast conditions the remaining 34%. Skies tend to cloud over as the month goes on.

	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
Clearer (%)	77	76	75	74	73	72	71	70	69	68	68	67	66	65	65	65	63	63	63	62	62	62	63	62	62	62	62	62	62	61
Cloudier (%)	23	24	25	26	27	28	29	30	31	32	32	33	34	35	35	35	37	37	37	38	38	38	37	38	38	38	38	38	38	39

	Clearer (%)	Cloudier (%)
1	77	23
2	76	24
3	75	25
4	74	26
5	73	27
6	72	28
7	71	29
8	70	30
9	69	31
10	68	32
11	68	32
12	67	33
13	66	34
14	65	35
15	65	35
16	65	35
17	63	37
18	63	37
19	63	37
20	62	38
21	62	38
22	62	38
23	63	37
24	62	38
25	62	38
26	62	38
27	62	38
28	62	38
29	62	38
30	61	39

Chance of precipitation in September

Any precipitation

Terni gets around 82 mm of rain over 9.4 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 32% and peaks near 34% on the wettest days.

	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
Rain chance (%)	27	28	28	29	29	30	30	31	31	31	32	32	33	33	33	33	34	34	34	34	34	34	33	33	33	33	33	33	33	33

	Rain chance (%)
1	27
2	28
3	28
4	29
5	29
6	30
7	30
8	31
9	31
10	31
11	32
12	32
13	33
14	33
15	33
16	33
17	34
18	34
19	34
20	34
21	34
22	34
23	33
24	33
25	33
26	33
27	33
28	33
29	33
30	33

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 60% 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
Dry (%)	44	46	47	49	50	52	53	53	55	55	55	56	57	58	59	60	60	61	62	63	65	66	67	69	69	70	72	73	75	76
Comfortable (%)	42	42	41	41	40	39	39	39	38	38	38	37	37	36	35	34	34	33	32	31	30	29	28	27	27	26	25	24	23	22
Humid (%)	13	12	11	11	10	9	8	8	7	7	7	7	6	6	6	6	6	6	6	6	5	5	5	4	4	4	3	3	2	2

	Dry (%)	Comfortable (%)	Humid (%)
1	44	42	13
2	46	42	12
3	47	41	11
4	49	41	11
5	50	40	10
6	52	39	9
7	53	39	8
8	53	39	8
9	55	38	7
10	55	38	7
11	55	38	7
12	56	37	7
13	57	37	6
14	58	36	6
15	59	35	6
16	60	34	6
17	60	34	6
18	61	33	6
19	62	32	6
20	63	31	6
21	65	30	5
22	66	29	5
23	67	28	5
24	69	27	4
25	69	27	4
26	70	26	4
27	72	25	3
28	73	24	3
29	75	23	2
30	76	22	2

Wind in September

Winds average 6 km/h in September.

Across September, daily wind ranges from about 6 km/h on the calmest days to 6 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
Wind speed (km/h)	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6
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

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

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 hours 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 84 minutes over September. Sunrise moves from 5:39 AM to 6:11 AM, and sunset from 6:40 PM to 5:47 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
Daylight (h)	13.0	13.0	12.9	12.9	12.8	12.8	12.7	12.7	12.6	12.6	12.5	12.5	12.4	12.4	12.3	12.3	12.2	12.2	12.1	12.1	12.0	12.0	11.9	11.9	11.8	11.8	11.7	11.7	11.6	11.6
Sunrise (AM)	5:39	5:40	5:41	5:42	5:43	5:44	5:45	5:46	5:48	5:49	5:50	5:51	5:52	5:53	5:54	5:55	5:56	5:57	5:59	6:00	6:01	6:02	6:03	6:04	6:05	6:06	6:08	6:09	6:10	6:11
Sunset (PM)	6:40	6:38	6:36	6:34	6:32	6:31	6:29	6:27	6:25	6:23	6:21	6:20	6:18	6:16	6:14	6:12	6:10	6:09	6:07	6:05	6:03	6:01	5:59	5:57	5:56	5:54	5:52	5:50	5:48	5:47

	Daylight (h)	Sunrise (AM)	Sunset (PM)
1	13.0	5:39	6:40
2	13.0	5:40	6:38
3	12.9	5:41	6:36
4	12.9	5:42	6:34
5	12.8	5:43	6:32
6	12.8	5:44	6:31
7	12.7	5:45	6:29
8	12.7	5:46	6:27
9	12.6	5:48	6:25
10	12.6	5:49	6:23
11	12.5	5:50	6:21
12	12.5	5:51	6:20
13	12.4	5:52	6:18
14	12.4	5:53	6:16
15	12.3	5:54	6:14
16	12.3	5:55	6:12
17	12.2	5:56	6:10
18	12.2	5:57	6:09
19	12.1	5:59	6:07
20	12.1	6:00	6:05
21	12.0	6:01	6:03
22	12.0	6:02	6:01
23	11.9	6:03	5:59
24	11.9	6:04	5:57
25	11.8	6:05	5:56
26	11.8	6:06	5:54
27	11.7	6:08	5:52
28	11.7	6:09	5:50
29	11.6	6:10	5:48
30	11.6	6:11	5:47

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.45 kWh/m².

For context, solar energy here swings from a low near 1.54 kWh/m² to a high of 6.92 kWh/m² in July across the year — September's 4.45 kWh/m² falls in the middle.

	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
Solar energy (kWh/m²)	5.3	5.2	5.1	5.1	5.0	5.0	4.9	4.8	4.8	4.7	4.7	4.6	4.6	4.5	4.5	4.4	4.3	4.3	4.3	4.2	4.2	4.1	4.0	4.0	4.0	3.9	3.9	3.8	3.8	3.7
Level	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate

	Solar energy (kWh/m²)	Level
1	5.3	Bright
2	5.2	Bright
3	5.1	Bright
4	5.1	Bright
5	5.0	Bright
6	5.0	Bright
7	4.9	Bright
8	4.8	Bright
9	4.8	Bright
10	4.7	Bright
11	4.7	Bright
12	4.6	Bright
13	4.6	Bright
14	4.5	Bright
15	4.5	Bright
16	4.4	Bright
17	4.3	Bright
18	4.3	Bright
19	4.3	Bright
20	4.2	Bright
21	4.2	Bright
22	4.1	Bright
23	4.0	Bright
24	4.0	Bright
25	4.0	Moderate
26	3.9	Moderate
27	3.9	Moderate
28	3.8	Moderate
29	3.8	Moderate
30	3.7	Moderate

Planning a trip in September

Is September a good time to visit Terni?

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

7.1

Sightseeing

3rd-best month of the year

5.5

Beach & pool

4th-best month of the year

September is one of the better times to visit Terni for general sightseeing.

What to pack for Terni in September

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

In September, Terni sees daytime highs around 23°C and nights near 13°C. Worth packing: light clothes and rain gear. About 9 days see rain.

light clothesrain gear

UV index in Terni in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September 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 Terni peaks around July 15 at about 10 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 22 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	5	7	9	10	8	6	4	2	1
Level	Low	Moderate	High	Moderate	High	Very high	Very high	Very high	High	Moderate	Moderate	Low

	UV index (midday)	Level
Jan	1	Low
Feb	3	Moderate
Mar	5	High
Apr	5	Moderate
May	7	High
Jun	9	Very high
Jul	10	Very high
Aug	8	Very high
Sep	6	High
Oct	4	Moderate
Nov	2	Moderate
Dec	1	Low

Air quality in Terni 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 Terni is worst in April — around 21 µg/m³ PM2.5 (moderate), and holds fairly steady the rest of the year.

Seasonal pattern from CAMS reanalysis, scaled to Terni's WHO annual average of 17.3 µg/m³.

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
PM2.5 (µg/m³)	19	19	21	21	19	18	14	16	14	16	15	16
Level	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate

	PM2.5 (µg/m³)	Level
Jan	19	Moderate
Feb	19	Moderate
Mar	21	Moderate
Apr	21	Moderate
May	19	Moderate
Jun	18	Moderate
Jul	14	Moderate
Aug	16	Moderate
Sep	14	Moderate
Oct	16	Moderate
Nov	15	Moderate
Dec	16	Moderate

Location & terrain

Where is Terni?

Terni sits at 42.6°N, 12.6°E, 130 m above sea level, in Italy. The nearest listed city is Spoleto, 21 km away.

Topography around Terni

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

Within 3 km, the terrain around Terni has only modest variations in elevation — a maximum elevation change of 220 m around an average of 159 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,226 m; within 80 km, extreme variations in elevation — a maximum elevation change of 2,840 m.

The land around Terni is covered by trees (44%) and artificial surfaces (40%) within 3 km, trees (74%) within 16 km, and trees (64%) within 80 km.

3 km

220 m

trees 44%

16 km

1,226 m

trees 74%

80 km

2,840 m

trees 64%

treesshrubsgrasslandcroplandartificial surfaceswater

← August Terni year-round climate October →Best places to visit in September

September weather nearby: Spoleto 21 km · Rieti 25 km · Todi 31 km · Foligno 44 km · Viterbo 47 km · Assisi 56 km · Bastia umbra 56 km · Monterotondo 57 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 Terni (42.5633°, 12.6433°, elevation 130 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	26	15
2	26	15
3	26	15
4	25	15
5	25	14
6	25	14
7	25	14
8	25	14
9	24	14
10	24	14
11	24	14
12	24	14
13	24	13
14	24	13
15	23	13
16	23	13
17	23	13
18	23	13
19	23	13
20	22	13
21	22	13
22	22	12
23	22	12
24	22	12
25	22	12
26	21	12
27	21	12
28	21	12
29	21	12
30	21	11

	Clearer (%)	Cloudier (%)
1	77	23
2	76	24
3	75	25
4	74	26
5	73	27
6	72	28
7	71	29
8	70	30
9	69	31
10	68	32
11	68	32
12	67	33
13	66	34
14	65	35
15	65	35
16	65	35
17	63	37
18	63	37
19	63	37
20	62	38
21	62	38
22	62	38
23	63	37
24	62	38
25	62	38
26	62	38
27	62	38
28	62	38
29	62	38
30	61	39

	Rain chance (%)
1	27
2	28
3	28
4	29
5	29
6	30
7	30
8	31
9	31
10	31
11	32
12	32
13	33
14	33
15	33
16	33
17	34
18	34
19	34
20	34
21	34
22	34
23	33
24	33
25	33
26	33
27	33
28	33
29	33
30	33

	Dry (%)	Comfortable (%)	Humid (%)
1	44	42	13
2	46	42	12
3	47	41	11
4	49	41	11
5	50	40	10
6	52	39	9
7	53	39	8
8	53	39	8
9	55	38	7
10	55	38	7
11	55	38	7
12	56	37	7
13	57	37	6
14	58	36	6
15	59	35	6
16	60	34	6
17	60	34	6
18	61	33	6
19	62	32	6
20	63	31	6
21	65	30	5
22	66	29	5
23	67	28	5
24	69	27	4
25	69	27	4
26	70	26	4
27	72	25	3
28	73	24	3
29	75	23	2
30	76	22	2

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

	Clearer (%)	Cloudier (%)
1	77	23
2	76	24
3	75	25
4	74	26
5	73	27
6	72	28
7	71	29
8	70	30
9	69	31
10	68	32
11	68	32
12	67	33
13	66	34
14	65	35
15	65	35
16	65	35
17	63	37
18	63	37
19	63	37
20	62	38
21	62	38
22	62	38
23	63	37
24	62	38
25	62	38
26	62	38
27	62	38
28	62	38
29	62	38
30	61	39

	Rain chance (%)
1	27
2	28
3	28
4	29
5	29
6	30
7	30
8	31
9	31
10	31
11	32
12	32
13	33
14	33
15	33
16	33
17	34
18	34
19	34
20	34
21	34
22	34
23	33
24	33
25	33
26	33
27	33
28	33
29	33
30	33

	Dry (%)	Comfortable (%)	Humid (%)
1	44	42	13
2	46	42	12
3	47	41	11
4	49	41	11
5	50	40	10
6	52	39	9
7	53	39	8
8	53	39	8
9	55	38	7
10	55	38	7
11	55	38	7
12	56	37	7
13	57	37	6
14	58	36	6
15	59	35	6
16	60	34	6
17	60	34	6
18	61	33	6
19	62	32	6
20	63	31	6
21	65	30	5
22	66	29	5
23	67	28	5
24	69	27	4
25	69	27	4
26	70	26	4
27	72	25	3
28	73	24	3
29	75	23	2
30	76	22	2

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

	Clearer (%)	Cloudier (%)
1	77	23
2	76	24
3	75	25
4	74	26
5	73	27
6	72	28
7	71	29
8	70	30
9	69	31
10	68	32
11	68	32
12	67	33
13	66	34
14	65	35
15	65	35
16	65	35
17	63	37
18	63	37
19	63	37
20	62	38
21	62	38
22	62	38
23	63	37
24	62	38
25	62	38
26	62	38
27	62	38
28	62	38
29	62	38
30	61	39

	Rain chance (%)
1	27
2	28
3	28
4	29
5	29
6	30
7	30
8	31
9	31
10	31
11	32
12	32
13	33
14	33
15	33
16	33
17	34
18	34
19	34
20	34
21	34
22	34
23	33
24	33
25	33
26	33
27	33
28	33
29	33
30	33

	Dry (%)	Comfortable (%)	Humid (%)
1	44	42	13
2	46	42	12
3	47	41	11
4	49	41	11
5	50	40	10
6	52	39	9
7	53	39	8
8	53	39	8
9	55	38	7
10	55	38	7
11	55	38	7
12	56	37	7
13	57	37	6
14	58	36	6
15	59	35	6
16	60	34	6
17	60	34	6
18	61	33	6
19	62	32	6
20	63	31	6
21	65	30	5
22	66	29	5
23	67	28	5
24	69	27	4
25	69	27	4
26	70	26	4
27	72	25	3
28	73	24	3
29	75	23	2
30	76	22	2