Brooklin weather in September

In September, Brooklin sees average daytime highs of 21°C and overnight lows near 11°C, with 80 mm of rain across 9.4 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 33% 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 Brooklin's 3rd-clearest and 9th-windiest month. For the whole year in context, see Brooklin's year-round climate.

Daytime high
21°
4th warmest
Overnight low
11°
9th coldest
Rainfall
80 mm
9.4 wet days
Daylight
12 h 18 min
6:01 AM – 6:19 PM
Cloud cover
56%
3rd clearest
Wind
12 km/h
9th windiest
Solar energy
4.19 kWh/m²
Travel score
6.5
out of 10

Brooklin is human settlement in Whitby, Ontario, Canada.

Founded
1820

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 Brooklin 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 26°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)
12314
22314
32313
42313
52313
62313
72213
82213
92212
102212
112212
122212
132112
142111
152111
162111
172111
182011
192010
202010
212010
222010
231910
24199
25199
26189
27189
28189
29188
30178

How September really feels in Brooklin

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.

Brooklin 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-2° / -10°6410.68.89.10.0
Feb-1° / -10°518.26.910.20.0
Mar / -5°6110.35.711.60.2
Apr11° / 8411.52.113.22.7
May18° / 8111.2014.55.5
Jun23° / 13°9311.4015.26.5
Jul26° / 16°8811.2014.96.6
Aug25° / 15°8510.2013.86.9
Sep21° / 11°809.4012.36.5
Oct13° / 8311.40.310.83.7
Nov / -1°7310.639.40.7
Dec / -6°6510.67.38.80.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 33% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 17% 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 (%)
15446
25347
35347
45347
55248
65248
75248
85149
95149
105149
115149
125050
135050
145050
155050
165050
174951
184951
194951
205050
215050
224951
234852
244852
254753
264555
274555
284555
294555
304456

Chance of precipitation in September

Any precipitation

Brooklin gets around 80 mm of rain over 9.4 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 32% and peaks near 37% on the wettest days.

0%10%20%30%40%50%151015202530
Rain chance (%)
130
230
330
430
531
631
731
831
931
1031
1131
1231
1331
1430
1530
1630
1730
1830
1930
2030
2130
2231
2332
2432
2533
2634
2735
2836
2936
3037

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 60% 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 (%)
1392719131
2412718131
3432618121
4442617111
5462517111
6472516101
7492516101
850241691
952241581
1053231581
1155231570
1257221470
1358221460
1459211460
1561211350
1661211350
1763201340
1863201340
1965191240
2067181230
2167181230
2269171130
2370171120
2472161020
2572161020
267515910
277515910
287714810
297813810
307913710

Wind in September

Winds average 12 km/h in September.

Across September, daily wind ranges from about 11 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
111calm
211calm
311calm
411calm
511calm
611calm
711calm
811calm
912calm
1012calm
1112calm
1212calm
1312calm
1412calm
1512calm
1612calm
1712calm
1812calm
1912calm
2012light breeze
2112light breeze
2212light breeze
2312light breeze
2412light breeze
2512light breeze
2612light breeze
2712light breeze
2813light breeze
2913light breeze
3013light breeze

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 5:44 AM to 6:18 AM, and sunset from 6:47 PM to 5:52 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.15:446:47
213.05:456:46
313.05:466:44
412.95:476:42
512.95:486:40
612.85:496:38
712.85:516:36
812.75:526:34
912.75:536:33
1012.65:546:31
1112.65:556:29
1212.55:576:27
1312.55:586:25
1412.45:596:23
1512.36:006:21
1612.36:016:19
1712.26:026:17
1812.26:046:15
1912.16:056:13
2012.16:066:11
2112.06:076:09
2212.06:086:08
2311.96:106:06
2411.96:116:04
2511.86:126:02
2611.86:136:00
2711.76:145:58
2811.76:165:56
2911.66:175:54
3011.66:185:52

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.19 kWh/m².

For context, solar energy here swings from a low near 1.31 kWh/m² to a high of 6.39 kWh/m² in June across the year — September's 4.19 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.8Bright
24.8Bright
34.7Bright
44.7Bright
54.7Bright
64.6Bright
74.6Bright
84.5Bright
94.5Bright
104.4Bright
114.4Bright
124.3Bright
134.3Bright
144.3Bright
154.2Bright
164.2Bright
174.1Bright
184.1Bright
194.0Bright
204.0Moderate
213.9Moderate
223.9Moderate
233.8Moderate
243.8Moderate
253.7Moderate
263.7Moderate
273.6Moderate
283.6Moderate
293.5Moderate
303.5Moderate
Planning a trip in September

Is September a good time to visit Brooklin?

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
4th-best month of the year

September is a reasonable time to visit Brooklin for sightseeing.

What to pack for Brooklin in September

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

In September, Brooklin sees daytime highs around 21°C and nights near 11°C. Worth packing: rain gear. About 9 days see rain.

rain gear

Sea temperature near Brooklin 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 offshore is warmest in August at about 21°C and coldest in March near 3°C.

It's comfortable for a long swim from Jul 27 to Sep 2 — about 1.2 months when the water holds above 20°C.

0°10°20°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarm
Sea temperature (°C)Comfort
Jan4Bracing
Feb3Bracing
Mar3Bracing
Apr4Bracing
May7Bracing
Jun14Bracing
Jul19Cool
Aug21Refreshing
Sep19Cool
Oct13Bracing
Nov8Bracing
Dec5Bracing

UV index in Brooklin 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 Brooklin peaks around June 20 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 7 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighModerateLowJun 20UV 8Dec 21UV 1
UV index (midday)Level
Jan1Low
Feb2Low
Mar4Moderate
Apr5High
May6High
Jun8Very high
Jul7Very high
Aug6High
Sep5High
Oct3Moderate
Nov2Low
Dec1Low

Air quality in Brooklin 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 Brooklin is worst in June — around 16 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (December, 8 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJun 1616 µg/m³Dec 108 µg/m³
PM2.5 (µg/m³)Level
Jan9Good
Feb12Good
Mar14Moderate
Apr14Moderate
May16Moderate
Jun16Moderate
Jul16Moderate
Aug14Moderate
Sep12Moderate
Oct8Good
Nov8Good
Dec8Good
Location & terrain

Where is Brooklin?

Brooklin sits at 44.0°N, 79.0°W, 164 m above sea level, in Canada. The nearest listed city is Whitby, 9.0 km away.

Topography around Brooklin

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

Within 3 km, the terrain around Brooklin has only modest variations in elevation — a maximum elevation change of 103 m around an average of 172 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 337 m; within 80 km, significant variations in elevation — a maximum elevation change of 461 m.

The land around Brooklin is covered by cropland (35%), trees (27%) and grassland (20%) within 3 km, trees (35%), cropland (23%) and grassland (20%) within 16 km, and water (38%) and trees (25%) within 80 km.

3 km
103 m
16 km
337 m
80 km
461 m
treesgrasslandcroplandartificial surfacesbare terrainwaterwetland
September weather nearby: Whitby 9.0 km · Oshawa 11 km · Ajax 13 km · Pickering 15 km · Uxbridge 20 km · Bowmanville 23 km · Stouffville 23 km · Rouge 24 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 Brooklin (43.9583°, -78.9597°, elevation 164 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).