Bastia weather in September

In September, Bastia sees average daytime highs of 22°C and overnight lows near 21°C, with 46 mm of rain across 6.3 wet days and about 12.3 hours of daylight. It is the 3rd-warmest and 8th-wettest month of the year here.

Highs ease over the month, from about 24°C in the first days to 21°C by the end. The sky is clear or mostly clear about 61% of the time in September, and the air most often feels humid.

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 Bastia's 4th-clearest and 8th-windiest month. For the whole year in context, see Bastia's year-round climate.

Daytime high
22°
3rd warmest
Overnight low
21°
10th coldest
Rainfall
46 mm
6.3 wet days
Daylight
12 h 18 min
6:08 AM – 6:25 PM
Cloud cover
36%
4th clearest
Wind
13 km/h
8th windiest
Solar energy
4.76 kWh/m²
Travel score
7.7
out of 10
Air quality
Good
PM2.5 8.7 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 24°C in the first days to 21°C by the end.

A typical September day in Bastia reaches about 22°C in the afternoon and slips back to 21°C overnight — a 2°C spread between the day's warmth and the night's chill. On most days the high lands between 20°C and 24°C. Set against its neighbours, September runs about 3°C cooler than August and about 3°C warmer than October.

15°20°25°30°151015202530
Avg high (°C)Avg low (°C)
12422
22422
32422
42422
52322
62322
72322
82322
92321
102321
112321
122321
132321
142221
152221
162221
172221
182220
192220
202220
212220
222220
232220
242120
252120
262120
272120
282119
292119
302119

Bastia weather by month

How September compares with the rest of the year at a glance. September is the 3rd-warmest and 8th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan12° / 10°578.59.23.3
Feb12° / 10°51710.33.3
Mar13° / 11°557.311.63.9
Apr15° / 13°497.713.14.8
May18° / 16°375.614.46.6
Jun22° / 20°243.315.18.2
Jul24° / 23°91.514.89.2
Aug25° / 23°112.313.78.8
Sep22° / 21°466.312.37.7
Oct19° / 18°809.110.86.5
Nov16° / 14°9911.39.64.8
Dec13° / 11°7510.28.93.8

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 61% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 14% of September, with mostly cloudy or overcast conditions the remaining 25%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
18416
28416
38416
48317
58317
68119
78119
88020
97921
107822
117822
127624
137525
147525
157426
167327
177228
187228
197129
207129
217030
227030
237030
247030
256931
266931
276931
286832
296832
306733

Chance of precipitation in September

Any precipitation

Bastia gets around 46 mm of rain over 6.3 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 21% and peaks near 27% on the wettest days. The odds climb toward the end of the month.

0%10%20%30%40%151015202530
Rain chance (%)
113
214
314
414
515
615
716
817
918
1018
1119
1220
1321
1421
1522
1623
1724
1824
1925
2025
2125
2226
2326
2426
2526
2626
2727
2827
2927
3027

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the humid band about 32% of days. Sticky, muggy-or-worse air turns up on roughly 34% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1513273420
2614283518
3614293515
4715303513
5716303611
6716313610
781731368
881731377
991831376
1091830375
11101930374
12101930374
13112029373
14112029363
15122129353
16132130343
17142230322
18152230312
19162331292
20172331272
21172432252
22182433231
23192534221
24192535201
25192636181
26202636171
27202737161
28212737151
29212837140
30212837130

Wind in September

Winds average 13 km/h in September.

Across September, daily wind ranges from about 12 km/h on the calmest days to 14 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202530
Wind speed (km/h)Feels
112light breeze
212light breeze
313light breeze
413light breeze
513light breeze
613light breeze
713light breeze
813light breeze
913light breeze
1013light breeze
1113light breeze
1213light breeze
1313light breeze
1413light breeze
1513light breeze
1613light breeze
1713light breeze
1813light breeze
1913light breeze
2014light breeze
2114light breeze
2214light breeze
2314light breeze
2414light breeze
2514light breeze
2614light breeze
2714light breeze
2814light breeze
2914light breeze
3014light breeze

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 5:51 AM to 6:24 AM, and sunset from 6:52 PM to 5:59 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.05:516:52
213.05:526:51
312.95:546:49
412.95:556:47
512.85:566:45
612.85:576:43
712.75:586:42
812.75:596:40
912.66:006:38
1012.66:016:36
1112.56:026:34
1212.56:046:32
1312.46:056:31
1412.46:066:29
1512.36:076:27
1612.36:086:25
1712.26:096:23
1812.26:106:21
1912.16:116:19
2012.16:126:18
2112.06:146:16
2212.06:156:14
2311.96:166:12
2411.96:176:10
2511.86:186:08
2611.86:196:07
2711.76:206:05
2811.76:216:03
2911.66:236:01
3011.66:245:59

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.76 kWh/m².

For context, solar energy here swings from a low near 1.62 kWh/m² to a high of 7.25 kWh/m² in July across the year — September's 4.76 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.6Bright
25.5Bright
35.5Bright
45.4Bright
55.3Bright
65.3Bright
75.2Bright
85.2Bright
95.1Bright
105.1Bright
115.0Bright
124.9Bright
134.9Bright
144.8Bright
154.8Bright
164.7Bright
174.7Bright
184.6Bright
194.5Bright
204.5Bright
214.4Bright
224.4Bright
234.3Bright
244.3Bright
254.2Bright
264.2Bright
274.1Bright
284.1Bright
294.0Bright
304.0Moderate
Planning a trip in September

Hazard calendar for Bastia

In seasonPeak

In September, Bastia sits inside its rainy season season. The full year is below, with each hazard's peak months called out.

Bastia's rainy season runs September–April, when most of the year's rain falls.

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

Is September a good time to visit Bastia?

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

7.7
Sightseeing
4th-best month of the year
5.5
Beach & pool
3rd-best month of the year

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

What to pack for Bastia in September

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

In September, Bastia sees daytime highs around 22°C and nights near 21°C. Worth packing: light clothes and sun protection. About 6 days see rain.

light clothessun protection

Sea temperature near Bastia in September

The nearest coast averages about 23°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 17 km away) is warmest in August at about 25°C and coldest in February near 14°C.

It's comfortable for a long swim from Jun 2 to Oct 24 — about 4.8 months when the water holds above 20°C.

10°15°20°25°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan14Bracing
Feb14Bracing
Mar14Bracing
Apr15Cool
May18Cool
Jun22Refreshing
Jul25Warm
Aug25Warm
Sep23Refreshing
Oct21Refreshing
Nov18Cool
Dec16Cool

UV index in Bastia 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 Bastia peaks around July 12 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 12UV 9Dec 23UV 1
UV index (midday)Level
Jan1Low
Feb3Moderate
Mar5Moderate
Apr5Moderate
May6High
Jun8Very high
Jul9Very high
Aug7High
Sep5High
Oct3Moderate
Nov2Moderate
Dec1Low
Location & terrain

Where is Bastia?

Bastia sits at 42.7°N, 9.5°E, 1 m above sea level, in France. The nearest listed city is Piombino, 91 km away.

Topography around Bastia

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

Within 3 km, the terrain around Bastia has large variations in elevation — a maximum elevation change of 629 m around an average of 120 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,311 m; within 80 km, extreme variations in elevation — a maximum elevation change of 2,620 m.

The land around Bastia is covered by water (47%) and trees (26%) within 3 km, water (53%) and trees (20%) within 16 km, and water (70%) within 80 km.

3 km
629 m
16 km
1,311 m
80 km
2,620 m
treesshrubsgrasslandcroplandartificial surfaceswater
September weather nearby: Piombino 91 km · Ajaccio 105 km · Cecina 110 km · Follonica 110 km · Rosignano Solvay-Castiglioncello 111 km · Livorno 118 km · Grosseto 136 km · Pisa 136 km

France travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type C / E
230 V · 50 Hz
Prices
≈ 77% of US
price level, 2025
GDP per capita
$48,986
2025
Happiness
6.6 / 10
World Happiness, 2025
Safe drinking water
100%
of population, 2024
Homicide rate
1.3
per 100k, 2023
Road deaths
5.1
per 100k/yr, 2019
Income group
High
World Bank
English
Moderate
EF EPI 539
Religion
Roman Catholic 47%none 33%Muslim 4%Protestant 2%

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 Bastia (42.7022°, 9.4512°, elevation 1 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. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).