Niagara-on-the-Lake weather in September

In September, Niagara-on-the-Lake sees average daytime highs of 21°C and overnight lows near 16°C, with 89 mm of rain across 10 wet days and about 12.3 hours of daylight. It is the 3rd-warmest and 5th-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 36% of the time in September, and the air most often feels dry.

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 Niagara-on-the-Lake's 3rd-clearest and 8th-windiest month. For the whole year in context, see Niagara-on-the-Lake's year-round climate.

Daytime high
21°
3rd warmest
Overnight low
16°
9th coldest
Rainfall
89 mm
10 wet days
Daylight
12 h 18 min
6:02 AM – 6:19 PM
Cloud cover
54%
3rd clearest
Wind
16 km/h
8th windiest
Solar energy
4.15 kWh/m²
Travel score
6.5
out of 10

Niagara-on-the-Lake is town in Niagara Region, Ontario, Canada.

Density
132/km²
people per km²
Founded
1781

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 Niagara-on-the-Lake reaches about 21°C in the afternoon and slips back to 16°C overnight — a 5°C spread between the day's warmth and the night's chill. On most days the high lands between 16°C and 25°C. Set against its neighbours, September runs about 3°C cooler than August and about 6°C warmer than October.

10°15°20°25°30°151015202530
Avg high (°C)Avg low (°C)
12318
22318
32318
42318
52318
62217
72217
82217
92217
102217
112217
122116
132116
142116
152116
162116
172115
182015
192015
202015
212015
222014
231914
241914
251914
261914
271913
281813
291813
301813

How September really feels in Niagara-on-the-Lake

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.

Niagara-on-the-Lake weather by month

How September compares with the rest of the year at a glance. September is the 3rd-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysSnow daysDaylight (hours)Travel score
Jan / -5°7713.211.39.20.0
Feb-0° / -6°609.87.810.20.0
Mar / -2°7310.54.911.60.0
Apr / 9611.61.713.21.6
May14° / 8211.5014.54.2
Jun21° / 16°9210.9015.16.3
Jul24° / 20°9210.5014.97.0
Aug24° / 19°7910.2013.87.1
Sep21° / 16°8910012.36.5
Oct14° / 10°9412.70.110.84.0
Nov / 8412.22.69.51.3
Dec / -1°8113.28.48.90.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 36% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 19% of September, with mostly cloudy or overcast conditions the remaining 45%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
16040
26040
36040
45941
55941
65941
75941
85842
95743
105842
115743
125644
135743
145743
155644
165644
175545
185545
195545
205545
215347
225347
235248
245248
255149
265149
275050
284951
294852
304852

Chance of precipitation in September

Any precipitation

Niagara-on-the-Lake gets around 89 mm of rain over 10 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 33% and peaks near 40% on the wettest days. The odds climb toward the end of the month.

0%10%20%30%40%50%151015202530
Rain chance (%)
130
230
331
431
532
632
732
833
933
1033
1133
1233
1332
1432
1532
1632
1731
1831
1932
2032
2132
2233
2334
2435
2536
2637
2738
2839
2940
3040

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 42% of days. Sticky, muggy-or-worse air turns up on roughly 13% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1192728225
2202727215
3222726204
4232726204
5252725194
6262824183
7282824183
8292823173
9312723162
10332723162
11342722152
12362722141
13382622131
14392621121
15412621111
16422620101
17442620101
1845261991
1947261980
2049251880
2151251770
2252251760
2354241660
2456241550
2557241450
2659231440
2760231340
2862231230
2964221130
3066221020

Wind in September

Winds average 16 km/h in September.

Across September, daily wind ranges from about 14 km/h on the calmest days to 17 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202530
Wind speed (km/h)Feels
114light breeze
214light breeze
314light breeze
415light breeze
515light breeze
615light breeze
715light breeze
815light breeze
915light breeze
1015light breeze
1115light breeze
1215light breeze
1315light breeze
1415light breeze
1516light breeze
1616light breeze
1716light breeze
1816light breeze
1916light breeze
2016light breeze
2116light breeze
2216light breeze
2316light breeze
2416light breeze
2517light breeze
2617light breeze
2717light breeze
2817light breeze
2917light breeze
3017light 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 5:45 AM to 6:18 AM, and sunset from 6:47 PM to 5:53 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.05:456:47
213.05:466:45
312.95:476:44
412.95:486:42
512.85:496:40
612.85:516:38
712.75:526:36
812.75:536:34
912.65:546:33
1012.65:556:31
1112.55:566:29
1212.55:576:27
1312.45:596:25
1412.46:006:23
1512.36:016:21
1612.36:026:19
1712.26:036:18
1812.26:046:16
1912.16:056:14
2012.16:076:12
2112.06:086:10
2212.06:096:08
2311.96:106:06
2411.96:116:04
2511.86:126:02
2611.86:136:01
2711.76:155:59
2811.76:165:57
2911.66:175:55
3011.66:185:53

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.15 kWh/m².

For context, solar energy here swings from a low near 1.28 kWh/m² to a high of 6.35 kWh/m² in June across the year — September's 4.15 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.8Bright
24.7Bright
34.7Bright
44.7Bright
54.6Bright
64.6Bright
74.5Bright
84.5Bright
94.4Bright
104.4Bright
114.3Bright
124.3Bright
134.3Bright
144.2Bright
154.2Bright
164.1Bright
174.1Bright
184.1Bright
194.0Bright
204.0Moderate
213.9Moderate
223.9Moderate
233.8Moderate
243.8Moderate
253.7Moderate
263.7Moderate
273.6Moderate
283.5Moderate
293.5Moderate
303.5Moderate
Planning a trip in September

Is September a good time to visit Niagara-on-the-Lake?

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

6.5
Sightseeing
3rd-best month of the year
3.8
Beach & pool
3rd-best month of the year

September is a reasonable time to visit Niagara-on-the-Lake for sightseeing.

What to pack for Niagara-on-the-Lake in September

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

In September, Niagara-on-the-Lake sees daytime highs around 21°C and nights near 16°C. Worth packing: rain gear. About 10 days see rain.

rain gear

Sea temperature near Niagara-on-the-Lake in September

The nearest coast averages about 19°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 14 km away) is warmest in August at about 22°C and coldest in February near 3°C.

It's comfortable for a long swim from Jul 17 to Sep 6 — about 1.7 months when the water holds above 20°C.

0°10°20°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarmcomfortable to swim
Sea temperature (°C)Comfort
Jan4Bracing
Feb3Bracing
Mar3Bracing
Apr4Bracing
May7Bracing
Jun15Bracing
Jul20Refreshing
Aug22Refreshing
Sep19Cool
Oct13Bracing
Nov8Bracing
Dec5Bracing

UV index in Niagara-on-the-Lake 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 Niagara-on-the-Lake peaks around June 19 at about 8 (very high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near December 21 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 highHighModerateLowJun 19UV 8Dec 21UV 1
UV index (midday)Level
Jan1Low
Feb2Moderate
Mar4Moderate
Apr5High
May6High
Jun8Very high
Jul7Very high
Aug6High
Sep5High
Oct3Moderate
Nov2Low
Dec1Low

Air quality in Niagara-on-the-Lake 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 Niagara-on-the-Lake is worst in May — around 21 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (November, 10 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodMay 2021 µg/m³Nov 2310 µg/m³
PM2.5 (µg/m³)Level
Jan11Good
Feb14Moderate
Mar17Moderate
Apr18Moderate
May21Moderate
Jun20Moderate
Jul20Moderate
Aug17Moderate
Sep16Moderate
Oct11Good
Nov10Good
Dec10Good
Location & terrain

Where is Niagara-on-the-Lake?

Niagara-on-the-Lake sits at 43.3°N, 79.1°W, 85 m above sea level, in Canada. The nearest listed city is St. Catharines, 16 km away.

Topography around Niagara-on-the-Lake

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Niagara-on-the-Lake.

Within 3 km, the terrain around Niagara-on-the-Lake has only modest variations in elevation — a maximum elevation change of 40 m around an average of 82 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 146 m; within 80 km, significant variations in elevation — a maximum elevation change of 540 m.

The land around Niagara-on-the-Lake is covered by water (47%) within 3 km, water (52%) within 16 km, and water (42%) and trees (24%) within 80 km.

3 km
40 m
16 km
146 m
80 km
540 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: St. Catharines 16 km · Niagara Falls 17 km · Thorold 18 km · Niagara Falls 18 km · Grand Island 27 km · North Tonawanda 30 km · Welland 33 km · Lockport 33 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 Niagara-on-the-Lake (43.2565°, -79.0853°, elevation 85 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).