Arlon weather in September

In September, Arlon sees average daytime highs of 18°C and overnight lows near 10°C, with 69 mm of rain across 10.5 wet days and about 12.4 hours of daylight. It is the 4th-warmest and 10th-wettest month of the year here.

Highs ease over the month, from about 19°C in the first days to 16°C by the end. The sky is clear or mostly clear about 19% 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 Arlon's 3rd-clearest and 9th-windiest month. For the whole year in context, see Arlon's year-round climate.

Daytime high
18°
4th warmest
Overnight low
10°
9th coldest
Rainfall
69 mm
10.5 wet days
Daylight
12 h 24 min
6:20 AM – 6:42 PM
Cloud cover
65%
3rd clearest
Wind
12 km/h
9th windiest
Solar energy
3.21 kWh/m²
Travel score
5.4
out of 10

Arlon is town in Arlon municipality, Belgium.

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 16°C by the end.

A typical September day in Arlon reaches about 18°C in the afternoon and slips back to 10°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between 13°C and 23°C. Set against its neighbours, September runs about 4°C cooler than August and about 5°C warmer than October.

10°15°20°25°151015202530
Avg high (°C)Avg low (°C)
11911
21911
31911
41911
51911
61911
71911
81910
91810
101810
111810
121810
131810
141810
151810
161810
17179
18179
19179
20179
21179
22179
23179
24169
25169
26169
27169
28169
29168
30158

How September really feels in Arlon

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.

Arlon weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 10th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -1°8212.748.40.0
Feb / -1°6811.14.69.80.1
Mar / 7112.62.211.51.6
Apr13° / 6312.10.613.43.3
May17° / 7613.9015.14.7
Jun20° / 11°7612.20165.7
Jul22° / 13°7612.9015.76.2
Aug22° / 13°7712.4014.26.2
Sep18° / 10°6910.5012.45.4
Oct13° / 7411.70.110.53.3
Nov / 7512.81.58.80.9
Dec / 98144.280.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 19% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 16% of September, with mostly cloudy or overcast conditions the remaining 65%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
13763
23763
33763
43763
53763
63664
73664
83664
93664
103763
113763
123763
133763
143763
153763
163763
173763
183763
193862
203763
213763
223664
233565
243466
253466
263367
273169
283070
292773
302773

Chance of precipitation in September

Any precipitation

Arlon gets around 69 mm of rain over 10.5 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 36% and peaks near 39% on the wettest days.

0%10%20%30%40%50%151015202530
Rain chance (%)
136
236
336
435
535
635
735
836
936
1036
1136
1236
1336
1436
1536
1636
1736
1836
1936
2036
2136
2236
2336
2436
2536
2637
2737
2838
2938
3039

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 83% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)
170246
272235
373234
474224
575223
676213
776213
878202
978202
1079192
1180182
1280182
1382171
1483161
1584151
1685141
1786131
1886131
1987121
2089110
2189110
2290100
2390100
249190
259190
269190
279190
289190
299190
309280

Wind in September

Winds average 12 km/h in September.

Across September, daily wind ranges from about 12 km/h on the calmest days to 13 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
112light breeze
212light breeze
312light breeze
412light breeze
512light breeze
612light breeze
712light 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
2013light breeze
2113light breeze
2213light breeze
2313light breeze
2413light breeze
2513light breeze
2613light breeze
2713light breeze
2813light breeze
2913light breeze
3013light 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 5:57 AM to 6:42 AM, and sunset from 7:16 PM to 6:10 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.35:577:16
213.25:597:13
313.26:007:11
413.16:027:09
513.16:037:07
613.06:057:05
712.96:067:02
812.96:087:00
912.86:096:58
1012.76:116:56
1112.76:136:53
1212.66:146:51
1312.66:166:49
1412.56:176:47
1512.46:196:44
1612.46:206:42
1712.36:226:40
1812.26:236:37
1912.26:256:35
2012.16:266:33
2112.06:286:31
2212.06:296:28
2311.96:316:26
2411.96:326:24
2511.86:346:22
2611.76:356:19
2711.76:376:17
2811.66:396:15
2911.56:406:13
3011.56:426:10

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 3.21 kWh/m².

For context, solar energy here swings from a low near 0.66 kWh/m² to a high of 5.46 kWh/m² in June across the year — September's 3.21 kWh/m² falls in the middle.

01234151015202530
Solar energy (kWh/m²)Level
13.8Moderate
23.8Moderate
33.7Moderate
43.7Moderate
53.6Moderate
63.6Moderate
73.5Moderate
83.5Moderate
93.5Moderate
103.4Moderate
113.4Moderate
123.4Moderate
133.3Moderate
143.3Moderate
153.2Moderate
163.2Moderate
173.1Moderate
183.1Moderate
193.1Moderate
203.0Moderate
213.0Moderate
222.9Moderate
232.9Moderate
242.8Moderate
252.8Moderate
262.7Moderate
272.6Moderate
282.6Moderate
292.5Moderate
302.5Moderate
Planning a trip in September

Is September a good time to visit Arlon?

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

5.4
Sightseeing
4th-best month of the year
1.6
Beach & pool
4th-best month of the year

September is a reasonable time to visit Arlon for sightseeing.

What to pack for Arlon in September

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

In September, Arlon sees daytime highs around 18°C and nights near 10°C. Worth packing: rain gear. About 11 days see rain.

rain gear

UV index in Arlon 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 Arlon peaks around July 16 at about 7 (very 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 7 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighModerateLowJul 16UV 7Jan 1UV 1
UV index (midday)Level
Jan1Low
Feb1Low
Mar3Moderate
Apr5Moderate
May6High
Jun7High
Jul7Very high
Aug6High
Sep4Moderate
Oct3Moderate
Nov1Low
Dec1Low

Air quality in Arlon 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 Arlon is worst in April — around 16 µg/m³ PM2.5 (moderate), about 1.8× the cleanest month (December, 9 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodApr 1516 µg/m³Dec 109 µg/m³
PM2.5 (µg/m³)Level
Jan11Good
Feb11Good
Mar15Moderate
Apr16Moderate
May14Moderate
Jun14Moderate
Jul12Moderate
Aug12Moderate
Sep12Moderate
Oct10Good
Nov9Good
Dec9Good
Location & terrain

Where is Arlon?

Arlon sits at 49.7°N, 5.8°E, 421 m above sea level, in Belgium. The nearest listed city is Esch-sur-Alzette, 24 km away.

Esch-sur-AlzetteLuxembourgDudelangeThionvilleYutzKonz

Topography around Arlon

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

Within 3 km, the terrain around Arlon has only modest variations in elevation — a maximum elevation change of 176 m around an average of 382 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 288 m; within 80 km, large variations in elevation — a maximum elevation change of 613 m.

The land around Arlon is covered by trees (40%) and grassland (30%) within 3 km, trees (46%) and grassland (34%) within 16 km, and trees (49%), grassland (25%) and cropland (22%) within 80 km.

3 km
176 m
16 km
288 m
80 km
613 m
treesgrasslandcroplandartificial surfaces
September weather nearby: Esch-sur-Alzette 24 km · Luxembourg 24 km · Dudelange 30 km · Hayange 43 km · Thionville 44 km · Yutz 45 km · Konz 55 km · Trier 60 km

Belgium travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type C / E
230 V · 50 Hz
Prices
≈ 81% of US
price level, 2025
GDP per capita
$60,750
2025
Happiness
6.9 / 10
World Happiness, 2025
Safe drinking water
100%
of population, 2024
Homicide rate
1.1
per 100k, 2021
Road deaths
5.8
per 100k/yr, 2019
Income group
High
World Bank
English
Very high
EF EPI 608
Religion
Roman Catholic 57%nonbeliever/agnostic 20%atheist 9%Muslim 7%

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 Arlon (49.6833°, 5.8167°, elevation 421 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).