Brockville weather in September

In September, Brockville sees average daytime highs of 21°C and overnight lows near 12°C, with 94 mm of rain across 10 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 Brockville's 1st-clearest and 8th-windiest month. For the whole year in context, see Brockville's year-round climate.

Daytime high
21°
4th warmest
Overnight low
12°
9th coldest
Rainfall
94 mm
10 wet days
Daylight
12 h 18 min
5:48 AM – 6:06 PM
Cloud cover
57%
1st clearest
Wind
11 km/h
8th windiest
Solar energy
3.96 kWh/m²
Travel score
6.5
out of 10

Brockville is city in Eastern Ontario, Canada.

Founded
1784

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 Brockville reaches about 21°C in the afternoon and slips back to 12°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 16°C and 27°C. Set against its neighbours, September runs about 4°C cooler than August and about 7°C warmer than October.

10°20°30°151015202530
Avg high (°C)Avg low (°C)
12414
22414
32314
42314
52314
62314
72314
82313
92213
102213
112213
122213
132212
142212
152112
162112
172112
182111
192111
202011
212011
222011
232010
241910
251910
261910
271910
281810
29189
30189

How September really feels in Brockville

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.

Brockville 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-3° / -11°7511.89.790.0
Feb-2° / -11°619.68.210.10.0
Mar / -5°7711.36.511.60.2
Apr12° / 10411.92.513.22.8
May19° / 8911.60.114.65.6
Jun23° / 13°10211.6015.36.5
Jul26° / 17°9611.90156.4
Aug25° / 16°9511.6013.96.7
Sep21° / 12°9410012.36.5
Oct14° / 10812.20.310.73.7
Nov / 8811.83.39.40.8
Dec / -5°8512.88.48.70.0

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 19% of September, with mostly cloudy or overcast conditions the remaining 50%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15248
25248
35248
45248
55248
65149
75149
85149
95149
105149
115149
125149
135248
145149
155149
165149
175149
185248
195248
205149
215149
225149
235050
245050
254852
264753
274654
284654
294555
304555

Chance of precipitation in September

Any precipitation

Brockville gets around 94 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 34% and peaks near 39% on the wettest days. The odds climb toward the end of the month.

0%10%20%30%40%50%151015202530
Rain chance (%)
130
230
330
430
531
631
732
832
932
1033
1133
1233
1333
1433
1533
1633
1733
1833
1934
2034
2134
2235
2335
2436
2536
2637
2738
2838
2939
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 54% of days. Sticky, muggy-or-worse air turns up on roughly 7% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1293024161
2313023151
3323022141
4343021141
5362921131
6372920121
7392820111
8412820111
9432720101
1045262091
1146251981
1248241971
1350231971
1451231961
1553221861
1655221850
1757211750
1858211740
1960201640
2061201540
2162201530
2264191430
2365191330
2468181220
2569181120
2671171020
277217920
287416820
297615810
307814710

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
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 5:30 AM to 6:05 AM, and sunset from 6:35 PM to 5:39 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.15:306:35
213.05:316:33
313.05:326:31
412.95:336:29
512.95:356:28
612.85:366:26
712.85:376:24
812.75:386:22
912.75:396:20
1012.65:416:18
1112.65:426:16
1212.55:436:14
1312.55:446:12
1412.45:466:10
1512.45:476:08
1612.35:486:06
1712.35:496:04
1812.25:506:02
1912.15:526:00
2012.15:535:58
2112.05:545:56
2212.05:555:54
2311.95:565:53
2411.95:585:51
2511.85:595:49
2611.86:005:47
2711.76:015:45
2811.76:035:43
2911.66:045:41
3011.66:055:39

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 3.96 kWh/m².

For context, solar energy here swings from a low near 1.2 kWh/m² to a high of 5.97 kWh/m² in June across the year — September's 3.96 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
94.3Bright
104.2Bright
114.2Bright
124.1Bright
134.1Bright
144.0Bright
154.0Bright
164.0Moderate
173.9Moderate
183.9Moderate
193.8Moderate
203.8Moderate
213.7Moderate
223.7Moderate
233.6Moderate
243.5Moderate
253.5Moderate
263.4Moderate
273.4Moderate
283.3Moderate
293.3Moderate
303.2Moderate
Planning a trip in September

Hazard calendar for Brockville

In seasonPeak

In September, Brockville sits inside its atlantic hurricane season. The full year is below, with each hazard's peak months called out.

Brockville sits in the Atlantic hurricane belt; the season peaks August–October.

Atlantic hurricane
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is September a good time to visit Brockville?

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

6.5
Sightseeing
2nd-best month of the year
4.0
Beach & pool
4th-best month of the year

September is a reasonable time to visit Brockville for sightseeing.

What to pack for Brockville in September

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

In September, Brockville sees daytime highs around 21°C and nights near 12°C. Worth packing: rain gear. About 10 days see rain.

rain gear

UV index in Brockville 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 Brockville 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 December 22 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 13UV 8Dec 22UV 1
UV index (midday)Level
Jan1Low
Feb2Moderate
Mar3Moderate
Apr5Moderate
May7High
Jun7High
Jul8Very high
Aug5Moderate
Sep5High
Oct3Moderate
Nov2Low
Dec1Low
Location & terrain

Where is Brockville?

Brockville sits at 44.6°N, 75.7°W, 93 m above sea level, in Canada. The nearest listed city is Watertown, 71 km away.

Topography around Brockville

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

Within 3 km, the terrain around Brockville has only modest variations in elevation — a maximum elevation change of 59 m around an average of 92 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 81 m; within 80 km, significant variations in elevation — a maximum elevation change of 597 m.

The land around Brockville is covered by trees (37%) and water (31%) within 3 km, trees (51%) within 16 km, and trees (63%) within 80 km.

3 km
59 m
16 km
81 m
80 km
597 m
treesgrasslandcroplandartificial surfacesbare terrainwaterwetland
September weather nearby: Watertown 71 km · Kingston 75 km · Stittsville 75 km · Bridlewood 78 km · Kanata 81 km · Nepean 83 km · Gloucester 84 km · Alta Vista 88 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 Brockville (44.5913°, -75.687°, elevation 93 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. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). 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).