Frosinone weather in September

In September, Frosinone sees average daytime highs of 23°C and overnight lows near 13°C, with 112 mm of rain across 10.9 wet days and about 12.3 hours of daylight. It is the 4th-warmest and 5th-wettest month of the year here.

Highs ease over the month, from about 25°C in the first days to 21°C by the end. The sky is clear or mostly clear about 40% 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 Frosinone's 4th-clearest and 10th-windiest month. For the whole year in context, see Frosinone's year-round climate.

Daytime high
23°
4th warmest
Overnight low
13°
9th coldest
Rainfall
112 mm
10.9 wet days
Daylight
12 h 18 min
5:53 AM – 6:09 PM
Cloud cover
49%
4th clearest
Wind
5 km/h
10th windiest
Solar energy
4.46 kWh/m²
Travel score
6.8
out of 10
Air quality
Elevated
PM2.5 17 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 25°C in the first days to 21°C by the end.

A typical September day in Frosinone reaches about 23°C in the afternoon and slips back to 13°C overnight — a 11°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.

10°15°20°25°30°151015202530
Avg high (°C)Avg low (°C)
12615
22614
32514
42514
52514
62514
72514
82414
92413
102413
112413
122413
132313
142313
152313
162313
172312
182312
192212
202212
212212
222212
232212
242212
252111
262111
272111
282111
292111
302111

How September really feels in Frosinone

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.

Frosinone weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / 939.81.69.31.6
Feb / 10010.3210.32.0
Mar13° / 11111.21.511.73.4
Apr16° / 12413.70.413.14.4
May20° / 10°10212.2014.36.1
Jun25° / 13°699.20157.2
Jul28° / 16°466.9014.77.2
Aug28° / 16°447.5013.76.8
Sep23° / 13°11210.9012.36.8
Oct19° / 14511.7010.95.8
Nov13° / 173130.29.73.5
Dec / 13810.91.191.9

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 40% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 25% of September, with mostly cloudy or overcast conditions the remaining 35%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
17624
27525
37426
47327
57129
67129
77030
86931
96832
106733
116634
126634
136535
146535
156436
166436
176337
186337
196238
206238
216238
226238
236139
246040
256040
266040
276040
285941
295941
305941

Chance of precipitation in September

Any precipitation

Frosinone gets around 112 mm of rain over 10.9 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 37% and peaks near 39% on the wettest days.

0%10%20%30%40%50%151015202530
Rain chance (%)
133
234
334
435
535
636
736
836
936
1037
1137
1237
1337
1438
1538
1638
1739
1839
1939
2039
2138
2238
2337
2437
2537
2636
2736
2836
2936
3036

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 48% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)
12745271
22945251
33145231
43245211
53446201
63546181
73746161
83846151
93946141
104046141
114146131
124145131
134245130
144344120
154543120
164642120
174741120
184940110
195138110
205337100
215436100
22573490
23583390
24603280
25623170
26643060
27652960
28672850
29692740
30702640

Wind in September

Winds average 5 km/h in September.

Across September, daily wind ranges from about 5 km/h on the calmest days to 5 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (km/h)Feels
15calm
25calm
35calm
45calm
55calm
65calm
75calm
85calm
95calm
105calm
115calm
125calm
135calm
145calm
155calm
165calm
175calm
185calm
195calm
205calm
215calm
225calm
235calm
245calm
255calm
265calm
275calm
285calm
295calm
305calm

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 5:37 AM to 6:08 AM, and sunset from 6:36 PM to 5:44 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.05:376:36
212.95:386:34
312.95:396:32
412.85:406:31
512.85:416:29
612.75:426:27
712.75:436:25
812.75:446:24
912.65:456:22
1012.65:466:20
1112.55:476:18
1212.55:486:16
1312.45:506:15
1412.45:516:13
1512.35:526:11
1612.35:536:09
1712.25:546:07
1812.25:556:06
1912.15:566:04
2012.15:576:02
2112.05:586:00
2212.05:595:58
2311.96:005:57
2411.96:015:55
2511.86:025:53
2611.86:035:51
2711.76:045:49
2811.76:065:48
2911.76:075:46
3011.66:085:44

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.46 kWh/m².

For context, solar energy here swings from a low near 1.65 kWh/m² to a high of 6.93 kWh/m² in July across the year — September's 4.46 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.3Bright
25.2Bright
35.2Bright
45.1Bright
55.0Bright
65.0Bright
74.9Bright
84.8Bright
94.8Bright
104.7Bright
114.7Bright
124.6Bright
134.6Bright
144.5Bright
154.5Bright
164.4Bright
174.4Bright
184.3Bright
194.3Bright
204.2Bright
214.2Bright
224.1Bright
234.1Bright
244.0Bright
254.0Moderate
263.9Moderate
273.9Moderate
283.9Moderate
293.8Moderate
303.8Moderate
Planning a trip in September

Is September a good time to visit Frosinone?

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

6.8
Sightseeing
3rd-best month of the year
5.2
Beach & pool
4th-best month of the year

September is a reasonable time to visit Frosinone for sightseeing.

What to pack for Frosinone in September

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

In September, Frosinone sees daytime highs around 23°C and nights near 13°C. Worth packing: light clothes and rain gear. About 11 days see rain.

light clothesrain gear

Sea temperature near Frosinone in September

The nearest coast averages about 24°C in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 49 km away) is warmest in August at about 26°C and coldest in February near 14°C.

It's comfortable for a long swim from May 29 to Nov 4 — about 5.3 months when the water holds above 20°C.

15°20°25°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan15Bracing
Feb14Bracing
Mar14Bracing
Apr16Cool
May19Cool
Jun22Refreshing
Jul25Warm
Aug26Warm
Sep24Refreshing
Oct22Refreshing
Nov19Cool
Dec17Cool

UV index in Frosinone 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 Frosinone 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.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateVery highModerateLowJul 15UV 10Dec 22UV 1
UV index (midday)Level
Jan1Low
Feb3Moderate
Mar5Moderate
Apr4Moderate
May7High
Jun9Very high
Jul10Very high
Aug8Very high
Sep6High
Oct4Moderate
Nov2Moderate
Dec1Low

Air quality in Frosinone 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 Frosinone 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 Frosinone's WHO annual average of 17 µg/m³.

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateApr 1121 µg/m³Nov 1715 µg/m³
PM2.5 (µg/m³)Level
Jan18Moderate
Feb18Moderate
Mar20Moderate
Apr21Moderate
May17Moderate
Jun17Moderate
Jul15Moderate
Aug18Moderate
Sep15Moderate
Oct15Moderate
Nov15Moderate
Dec15Moderate
Location & terrain

Where is Frosinone?

Frosinone sits at 41.6°N, 13.3°E, 291 m above sea level, in Italy. The nearest listed city is Sora, 24 km away.

Topography around Frosinone

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

Within 3 km, the terrain around Frosinone has only modest variations in elevation — a maximum elevation change of 162 m around an average of 192 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,425 m; within 80 km, extreme variations in elevation — a maximum elevation change of 2,771 m.

The land around Frosinone is covered by trees (51%) and artificial surfaces (29%) within 3 km, trees (64%) within 16 km, and trees (48%) and water (22%) within 80 km.

3 km
162 m
16 km
1,425 m
80 km
2,771 m
treesshrubsgrasslandcroplandartificial surfaceswater
September weather nearby: Sora 24 km · Sezze 28 km · Colleferro 30 km · Fondi 32 km · Terracina 40 km · Latina 41 km · Cisterna di Latina 43 km · Avezzano 44 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 Frosinone (41.6398°, 13.3411°, elevation 291 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. Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. 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).