Dieppe weather in September

In September, Dieppe sees average daytime highs of 18°C and overnight lows near 13°C, with 63 mm of rain across 11 wet days and about 12.4 hours of daylight. It is the 3rd-warmest and 6th-wettest month of the year here.

Highs ease over the month, from about 19°C in the first days to 17°C by the end. The sky is clear or mostly clear about 21% of the time in September, and the air most often feels dry.

Daylight stretches from about 13 h 18 min at the start of September to 11 h 30 min by month's end. Set against the rest of the year, September is Dieppe's 5th-clearest and 8th-windiest month. For the whole year in context, see Dieppe's year-round climate.

Daytime high
18°
3rd warmest
Overnight low
13°
10th coldest
Rainfall
63 mm
11 wet days
Daylight
12 h 24 min
6:39 AM – 7:01 PM
Cloud cover
63%
5th clearest
Wind
18 km/h
8th windiest
Solar energy
3.54 kWh/m²
Travel score
5.7
out of 10
Air quality
Moderate
PM2.5 11.3 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 19°C in the first days to 17°C by the end.

A typical September day in Dieppe reaches about 18°C in the afternoon and slips back to 13°C overnight — a 5°C spread between the day's warmth and the night's chill. On most days the high lands between 15°C and 22°C. Set against its neighbours, September runs about 2°C cooler than August and about 3°C warmer than October.

10°15°20°25°151015202530
Avg high (°C)Avg low (°C)
11915
21914
31914
41914
51914
61914
71914
81914
91914
101914
111914
121914
131914
141814
151813
161813
171813
181813
191813
201813
211813
221813
231813
241813
251813
261713
271713
281713
291712
301712

How September really feels in Dieppe

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.

Dieppe weather by month

How September compares with the rest of the year at a glance. September is the 3rd-warmest and 6th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / 7413.20.78.41.0
Feb / 6112.30.89.71.1
Mar10° / 5811.60.511.52.1
Apr12° / 55110.113.53.2
May15° / 10°6111.3015.14.4
Jun18° / 13°5810.40165.6
Jul20° / 15°5410.5015.76.3
Aug20° / 15°6911.1014.36.2
Sep18° / 13°6311012.45.7
Oct15° / 11°8914.4010.54.0
Nov11° / 9315.70.18.82.3
Dec / 10014.90.781.3

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 21% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 20% of September, with mostly cloudy or overcast conditions the remaining 59%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
14654
24654
34654
44654
54555
64456
74456
84258
94258
104258
114159
124159
134060
144159
154159
164159
174159
184159
194159
204060
214060
224060
234060
244060
253862
263763
273763
283565
293565
303367

Chance of precipitation in September

Any precipitation

Dieppe gets around 63 mm of rain over 11 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 46% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%151015202530
Rain chance (%)
132
232
332
433
533
633
734
834
935
1035
1135
1236
1336
1436
1536
1636
1737
1837
1937
2038
2138
2239
2340
2441
2542
2643
2744
2845
2946
3046

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.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)
1463914
2483814
3493714
4503614
5523513
6533413
7543313
8543313
9563212
10573112
11583012
12593011
13612910
14612910
1562299
1663298
1765287
1865296
1965296
2066295
2166304
2266304
2366313
2466313
2567312
2667312
2767312
2868311
2969301
3070291

Wind in September

Winds average 18 km/h in September.

Across September, daily wind ranges from about 18 km/h on the calmest days to 19 km/h at its breeziest. It stays fairly steady from day to day.

0510152025151015202530
Wind speed (km/h)Feels
118light breeze
218light breeze
318light breeze
418light breeze
518light breeze
618light breeze
718light breeze
818light breeze
918light breeze
1018light breeze
1118light breeze
1218light breeze
1318light breeze
1418light breeze
1518light breeze
1618light breeze
1718light breeze
1818light breeze
1918light breeze
2018light breeze
2118light breeze
2219light breeze
2319light breeze
2419light breeze
2519light breeze
2619light breeze
2719light breeze
2819light breeze
2919light breeze
3019light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 h 18 min at the start of September to 11 h 30 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 108 minutes over September. Sunrise moves from 6:16 AM to 7:01 AM, and sunset from 7:35 PM to 6:29 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.36:167:35
213.36:187:33
313.26:197:30
413.16:217:28
513.16:227:26
613.06:247:24
712.96:257:21
812.96:277:19
912.86:287:17
1012.76:307:15
1112.76:317:12
1212.66:337:10
1312.66:347:08
1412.56:367:06
1512.46:377:03
1612.46:397:01
1712.36:416:59
1812.26:426:56
1912.26:446:54
2012.16:456:52
2112.06:476:50
2212.06:486:47
2311.96:506:45
2411.96:516:43
2511.86:536:40
2611.76:556:38
2711.76:566:36
2811.66:586:34
2911.56:596:31
3011.57:016:29

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 3.54 kWh/m².

For context, solar energy here swings from a low near 0.75 kWh/m² to a high of 6.06 kWh/m² in June across the year — September's 3.54 kWh/m² falls in the middle.

012345151015202530
Solar energy (kWh/m²)Level
14.2Bright
24.2Bright
34.1Bright
44.1Bright
54.0Bright
64.0Bright
74.0Moderate
83.9Moderate
93.9Moderate
103.8Moderate
113.8Moderate
123.7Moderate
133.7Moderate
143.6Moderate
153.6Moderate
163.5Moderate
173.5Moderate
183.4Moderate
193.4Moderate
203.3Moderate
213.3Moderate
223.2Moderate
233.2Moderate
243.1Moderate
253.1Moderate
263.0Moderate
272.9Moderate
282.9Moderate
292.8Moderate
302.8Moderate
Planning a trip in September

Is September a good time to visit Dieppe?

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

5.7
Sightseeing
3rd-best month of the year
2.1
Beach & pool
3rd-best month of the year

September is a reasonable time to visit Dieppe for sightseeing.

What to pack for Dieppe in September

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

In September, Dieppe sees daytime highs around 18°C and nights near 13°C. Worth packing: rain gear. About 11 days see rain.

rain gear

Sea temperature near Dieppe in September

The nearest coast averages about 18°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 15 km away) is warmest in August at about 18°C and coldest in February near 8°C.

The water stays below 20°C all year — cool enough that most swimmers want a wetsuit.

5°10°15°20°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshing
Sea temperature (°C)Comfort
Jan8Bracing
Feb8Bracing
Mar8Bracing
Apr10Bracing
May12Bracing
Jun15Bracing
Jul17Cool
Aug18Cool
Sep18Cool
Oct16Cool
Nov13Bracing
Dec10Bracing

UV index in Dieppe in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 4 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Dieppe peaks around June 19 at about 7 (high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near January 1 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 6 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighModerateLowJun 19UV 7Jan 1UV 1
UV index (midday)Level
Jan1Low
Feb2Low
Mar3Moderate
Apr4Moderate
May6High
Jun7High
Jul6High
Aug7High
Sep4Moderate
Oct3Moderate
Nov1Low
Dec1Low

Air quality in Dieppe 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 Dieppe is worst in March — around 15 µg/m³ PM2.5 (moderate), about 1.8× the cleanest month (November, 8 µg/m³).

Seasonal pattern from CAMS reanalysis, scaled to Dieppe's WHO annual average of 11.3 µg/m³.

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodMar 2415 µg/m³Nov 168 µg/m³
PM2.5 (µg/m³)Level
Jan10Good
Feb11Good
Mar15Moderate
Apr15Moderate
May14Moderate
Jun12Moderate
Jul11Good
Aug11Good
Sep11Good
Oct9Good
Nov8Good
Dec9Good
Location & terrain

Where is Dieppe?

Dieppe sits at 49.9°N, 1.1°E, 9 m above sea level, in France. The nearest listed city is Mont-Saint-Aignan, 51 km away.

Topography around Dieppe

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

Within 3 km, the terrain around Dieppe has only modest variations in elevation — a maximum elevation change of 101 m around an average of 33 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 191 m; within 80 km, significant variations in elevation — a maximum elevation change of 265 m.

The land around Dieppe is covered by water (34%) and artificial surfaces (24%) within 3 km, water (43%) and cropland (29%) within 16 km, and cropland (38%) and water (29%) within 80 km.

3 km
101 m
16 km
191 m
80 km
265 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Mont-Saint-Aignan 51 km · Rouen 53 km · Fécamp 54 km · Canteleu 54 km · Le Petit-Quevilly 57 km · Sotteville-lès-Rouen 57 km · Abbeville 58 km · Le Grand-Quevilly 58 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 Dieppe (49.9216°, 1.0777°, elevation 9 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).