Les Coteaux weather in September

In September, Les Coteaux sees average daytime highs of 21°C and overnight lows near 11°C, with 87 mm of rain across 10.1 wet days and about 12.3 hours of daylight. It is the 4th-warmest and 6th-wettest month of the year here.

Highs ease over the month, from about 23°C in the first days to 18°C by the end. The sky is clear or mostly clear about 31% of the time in September, and the air most often feels dry.

Daylight stretches from about 13 h 06 min at the start of September to 11 h 36 min by month's end. Set against the rest of the year, September is Les Coteaux's 1st-clearest and 10th-windiest month. For the whole year in context, see Les Coteaux's year-round climate.

Daytime high
21°
4th warmest
Overnight low
11°
9th coldest
Rainfall
87 mm
10.1 wet days
Daylight
12 h 18 min
5:42 AM – 6:01 PM
Cloud cover
57%
1st clearest
Wind
11 km/h
10th windiest
Solar energy
3.92 kWh/m²
Travel score
6.4
out of 10

Les Coteaux is municipality in Montérégie, Quebec, Canada.

Density
1,200/km²
people per km²
Founded
1994

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 23°C in the first days to 18°C by the end.

A typical September day in Les Coteaux reaches about 21°C in the afternoon and slips back to 11°C overnight — a 10°C spread between the day's warmth and the night's chill. On most days the high lands between 15°C and 27°C. Set against its neighbours, September runs about 4°C cooler than August and about 8°C warmer than October.

10°20°30°151015202530
Avg high (°C)Avg low (°C)
12414
22413
32313
42313
52313
62313
72313
82312
92212
102212
112212
122212
132211
142111
152111
162111
172111
182111
192010
202010
212010
222010
231910
24199
25199
26199
27189
28189
29188
30178

How September really feels in Les Coteaux

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.

Les Coteaux weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 6th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan-4° / -13°7210.79.68.90.0
Feb-3° / -12°619.48.410.10.0
Mar / -6°7310.66.711.60.1
Apr12° / 10111.72.713.22.8
May19° / 9511.4014.65.7
Jun24° / 14°9711.6015.46.4
Jul26° / 16°8912.5015.16.3
Aug25° / 15°8710.9013.96.7
Sep21° / 11°8710.1012.36.4
Oct13° / 10511.60.510.73.6
Nov / -1°8311.73.49.30.6
Dec-1° / -8°8211.998.60.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 31% of the time in September, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 18% of September, with mostly cloudy or overcast conditions the remaining 51%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15248
25248
35248
45248
55149
65248
75149
85149
95248
105149
115149
125149
135149
145149
155149
165050
175050
185050
195050
204951
214951
224753
234753
244654
254555
264456
274456
284357
294258
304159

Chance of precipitation in September

Any precipitation

Les Coteaux gets around 87 mm of rain over 10.1 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 34% and peaks near 36% on the wettest days.

0%10%20%30%40%50%151015202530
Rain chance (%)
130
231
331
431
532
633
733
833
934
1034
1134
1234
1334
1434
1534
1634
1734
1834
1934
2034
2134
2234
2335
2435
2535
2635
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 61% of days. Sticky, muggy-or-worse air turns up on roughly 6% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1402819111
2412819111
3432818101
4442817101
546271791
647271691
749271681
850261581
951261571
1052251571
1155241461
1256241460
1358231450
1460221350
1560221350
1662211340
1763211240
1864201240
1965201140
2067191130
2169181030
2269181030
237117930
247416820
257416820
267615720
277714720
288013610
298212510
308311510

Wind in September

Winds average 11 km/h in September.

Across September, daily wind ranges from about 10 km/h on the calmest days to 11 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
110calm
210calm
310calm
410calm
511calm
611calm
711calm
811calm
911calm
1011calm
1111calm
1211calm
1311calm
1411calm
1511calm
1611calm
1711calm
1811calm
1911calm
2011calm
2111calm
2211calm
2311calm
2411calm
2511calm
2611calm
2711calm
2811calm
2911calm
3011calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 h 06 min 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 90 minutes over September. Sunrise moves from 5:23 AM to 6:00 AM, and sunset from 6:30 PM to 5:33 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.15:236:30
213.15:246:28
313.05:266:26
413.05:276:24
512.95:286:22
612.95:296:20
712.85:316:18
812.75:326:17
912.75:336:15
1012.65:346:13
1112.65:366:11
1212.55:376:09
1312.55:386:07
1412.45:396:05
1512.45:416:03
1612.35:426:01
1712.35:435:59
1812.25:445:57
1912.15:465:55
2012.15:475:53
2112.05:485:51
2212.05:495:49
2311.95:515:47
2411.95:525:45
2511.85:535:43
2611.85:555:41
2711.75:565:39
2811.75:575:37
2911.65:585:35
3011.66:005:33

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 3.92 kWh/m².

For context, solar energy here swings from a low near 1.22 kWh/m² to a high of 5.95 kWh/m² in June across the year — September's 3.92 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.6Bright
24.5Bright
34.5Bright
44.5Bright
54.4Bright
64.4Bright
74.3Bright
84.3Bright
94.2Bright
104.2Bright
114.1Bright
124.1Bright
134.0Bright
144.0Bright
154.0Moderate
163.9Moderate
173.9Moderate
183.8Moderate
193.8Moderate
203.7Moderate
213.7Moderate
223.6Moderate
233.5Moderate
243.5Moderate
253.4Moderate
263.4Moderate
273.3Moderate
283.3Moderate
293.2Moderate
303.2Moderate
Planning a trip in September

Is September a good time to visit Les Coteaux?

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

6.4
Sightseeing
2nd-best month of the year
3.9
Beach & pool
4th-best month of the year

September is a reasonable time to visit Les Coteaux for sightseeing.

What to pack for Les Coteaux in September

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

In September, Les Coteaux sees daytime highs around 21°C and nights near 11°C. Worth packing: rain gear. About 10 days see rain.

rain gear

UV index in Les Coteaux 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 Les Coteaux peaks around July 14 at about 8 (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 highModerateModerateLowJul 14UV 8Jan 1UV 1
UV index (midday)Level
Jan1Low
Feb2Low
Mar3Moderate
Apr4Moderate
May6High
Jun6High
Jul8Very high
Aug4Moderate
Sep5High
Oct3Moderate
Nov2Low
Dec1Low
Location & terrain

Where is Les Coteaux?

Les Coteaux sits at 45.3°N, 74.2°W, 44 m above sea level, in Canada. The nearest listed city is Salaberry-de-Valleyfield, 9.0 km away.

Topography around Les Coteaux

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

Within 3 km, the terrain around Les Coteaux has only modest variations in elevation — a maximum elevation change of 81 m around an average of 50 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 149 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,210 m.

The land around Les Coteaux is covered by cropland (50%) and trees (25%) within 3 km, cropland (53%) and trees (20%) within 16 km, and trees (54%) and cropland (29%) within 80 km.

3 km
81 m
16 km
149 m
80 km
1,210 m
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Salaberry-de-Valleyfield 9.0 km · Saint-Lazare 15 km · Vaudreuil-Dorion 20 km · Pierrefonds 33 km · Beaconsfield 33 km · Kirkland 34 km · L'Île-Bizard–Sainte-Geneviève 35 km · Pointe-Claire 37 km

Canada travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 83% of US
price level, 2025
GDP per capita
$55,698
2025
Happiness
6.7 / 10
World Happiness, 2025
Safe drinking water
97%
of population, 2024
Homicide rate
2
per 100k, 2023
Road deaths
5.3
per 100k/yr, 2019
Income group
High
World Bank
Religion
Christian 53%none 35%Muslim 5%Hindu 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 Les Coteaux (45.2834°, -74.2325°, elevation 44 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. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).