Saint-Lazare weather in September

In September, Saint-Lazare sees average daytime highs of 20°C and overnight lows near 10°C, with 96 mm of rain across 10.2 wet days and about 12.3 hours of daylight. It is the 4th-warmest and 7th-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 Saint-Lazare's 1st-clearest and 10th-windiest month. For the whole year in context, see Saint-Lazare's year-round climate.

Daytime high
20°
4th warmest
Overnight low
10°
9th coldest
Rainfall
96 mm
10.2 wet days
Daylight
12 h 18 min
5:41 AM – 6:00 PM
Cloud cover
58%
1st clearest
Wind
11 km/h
10th windiest
Solar energy
3.9 kWh/m²
Travel score
6.3
out of 10

Saint-Lazare is city in Montérégue, Quebec, Canada.

Density
295/km²
people per km²
Founded
1875

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 Saint-Lazare reaches about 20°C in the afternoon and slips back to 10°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 26°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)
12313
22313
32313
42312
52312
62212
72212
82212
92212
102211
112111
122111
132111
142111
152110
162010
172010
182010
192010
20209
21199
22199
23199
24199
25188
26188
27188
28188
29178
30177

How September really feels in Saint-Lazare

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.

Saint-Lazare weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 7th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan-5° / -14°7710.69.48.90.0
Feb-4° / -13°6298.310.10.0
Mar / -7°7510.4711.60.1
Apr11° / 10511.42.913.22.6
May19° / 10011.50.214.75.7
Jun24° / 13°10511.7015.46.4
Jul26° / 16°10012.5015.16.3
Aug25° / 15°9811.2013.96.7
Sep20° / 10°9610.2012.36.3
Oct13° / 10911.60.610.73.4
Nov / -2°8811.43.89.30.4
Dec-2° / -9°8611.69.18.60.0

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 16% of September, with mostly cloudy or overcast conditions the remaining 53%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15149
25050
35050
45149
55050
64951
75050
85050
95050
104951
114951
124951
134951
144852
154852
164852
174852
184753
194753
204753
214654
224654
234555
244456
254456
264258
274258
284258
294060
304060

Chance of precipitation in September

Any precipitation

Saint-Lazare gets around 96 mm of rain over 10.2 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 (%)
131
232
332
433
533
634
734
834
934
1034
1134
1234
1334
1434
1534
1634
1734
1833
1933
2034
2134
2234
2334
2434
2534
2635
2735
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 64% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1452618101
2462618101
347261791
449251691
550251681
651251581
753241571
854241471
955241461
1056231461
1158221361
1260221350
1361211350
1463211240
1564201240
1665191240
1767191130
1868181130
1968181130
2070171030
2171161030
227315930
237415920
247614820
257713820
267912720
278211610
288211610
298410510
30859510

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
510calm
610calm
710calm
810calm
910calm
1010calm
1110calm
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 5:59 AM, and sunset from 6:30 PM to 5:32 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.15:236:30
213.15:246:28
313.05:256:26
413.05:266:24
512.95:286:22
612.95:296:20
712.85:306:18
812.75:316:16
912.75:336:14
1012.65:346:12
1112.65:356:10
1212.55:366:08
1312.55:386:06
1412.45:396:04
1512.45:406:02
1612.35:416:00
1712.35:435:58
1812.25:445:56
1912.25:455:54
2012.15:475:52
2112.05:485:50
2212.05:495:48
2311.95:505:46
2411.95:525:44
2511.85:535:42
2611.85:545:40
2711.75:555:38
2811.75:575:36
2911.65:585:34
3011.65:595:32

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 3.9 kWh/m².

For context, solar energy here swings from a low near 1.22 kWh/m² to a high of 5.97 kWh/m² in June across the year — September's 3.9 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.6Bright
24.5Bright
34.5Bright
44.5Bright
54.4Bright
64.3Bright
74.3Bright
84.3Bright
94.2Bright
104.2Bright
114.1Bright
124.1Bright
134.0Bright
144.0Moderate
153.9Moderate
163.9Moderate
173.8Moderate
183.8Moderate
193.7Moderate
203.7Moderate
213.6Moderate
223.6Moderate
233.5Moderate
243.5Moderate
253.4Moderate
263.4Moderate
273.3Moderate
283.3Moderate
293.2Moderate
303.1Moderate
Planning a trip in September

Is September a good time to visit Saint-Lazare?

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

6.3
Sightseeing
3rd-best month of the year
3.5
Beach & pool
4th-best month of the year

September is a reasonable time to visit Saint-Lazare for sightseeing.

What to pack for Saint-Lazare in September

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

In September, Saint-Lazare sees daytime highs around 20°C and nights near 10°C. Worth packing: rain gear. About 10 days see rain.

rain gear

UV index in Saint-Lazare 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 Saint-Lazare peaks around July 13 at about 8 (very high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near January 10 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 7 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighModerateLowJul 13UV 8Jan 10UV 1
UV index (midday)Level
Jan1Low
Feb2Low
Mar4Moderate
Apr4Moderate
May6High
Jun6High
Jul8Very high
Aug4Moderate
Sep5High
Oct3Moderate
Nov2Low
Dec1Low
Location & terrain

Where is Saint-Lazare?

Saint-Lazare sits at 45.4°N, 74.1°W, 56 m above sea level, in Canada. The nearest listed city is Vaudreuil-Dorion, 8.0 km away.

Topography around Saint-Lazare

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

Within 3 km, the terrain around Saint-Lazare has only modest variations in elevation — a maximum elevation change of 77 m around an average of 67 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 257 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,210 m.

The land around Saint-Lazare is covered by trees (64%) within 3 km, trees (34%) and cropland (32%) within 16 km, and trees (52%) and cropland (31%) within 80 km.

3 km
77 m
16 km
257 m
80 km
1,210 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Vaudreuil-Dorion 8.0 km · Les Coteaux 15 km · Salaberry-de-Valleyfield 17 km · Pierrefonds 20 km · Beaconsfield 21 km · L'Île-Bizard–Sainte-Geneviève 21 km · Kirkland 22 km · Deux-Montagnes 23 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 Saint-Lazare (45.4001°, -74.1326°, elevation 56 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).