Orillia weather in September

In September, Orillia sees average daytime highs of 20°C and overnight lows near 11°C, with 84 mm of rain across 10.9 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 22°C in the first days to 17°C by the end. The sky is clear or mostly clear about 32% 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 Orillia's 3rd-clearest and 9th-windiest month. For the whole year in context, see Orillia's year-round climate.

Daytime high
20°
4th warmest
Overnight low
11°
9th coldest
Rainfall
84 mm
10.9 wet days
Daylight
12 h 18 min
6:03 AM – 6:21 PM
Cloud cover
58%
3rd clearest
Wind
11 km/h
9th windiest
Solar energy
3.97 kWh/m²
Travel score
6.1
out of 10

Orillia is city in Ontario, Canada.

Founded
1867

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 22°C in the first days to 17°C by the end.

A typical September day in Orillia reaches about 20°C in the afternoon and slips back to 11°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 14°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
32214
42213
52213
62213
72213
82213
92112
102112
112112
122112
132112
142111
152011
162011
172011
182011
192011
201910
211910
221910
231910
241810
25189
26189
27189
28179
29179
30178

How September really feels in Orillia

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.

Orillia 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° / -11°6511.911.590.0
Feb-3° / -11°5098.510.10.0
Mar / -6°6010.1711.60.0
Apr10° / 7911.13.113.22.4
May18° / 8711.1014.65.5
Jun23° / 13°9411015.36.6
Jul25° / 16°8811.70156.7
Aug24° / 15°8811.5013.96.8
Sep20° / 11°8410.9012.36.1
Oct13° / 8813.60.510.73.1
Nov / -1°7612.34.99.40.4
Dec-1° / -7°6512.910.78.70.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 32% 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 51%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15446
25446
35347
45446
55446
65347
75248
85347
95248
105149
115248
125149
135050
145050
155149
165149
175050
185050
194951
204951
214852
224852
234753
244654
254555
264456
274456
284357
294357
304258

Chance of precipitation in September

Any precipitation

Orillia gets around 84 mm of rain over 10.9 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 36% and peaks near 42% on the wettest days.

0%10%20%30%40%50%151015202530
Rain chance (%)
135
235
335
436
536
636
736
836
936
1036
1136
1236
1335
1435
1535
1634
1734
1834
1934
2035
2135
2236
2337
2438
2538
2639
2740
2841
2942
3042

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 57% of days. Sticky, muggy-or-worse air turns up on roughly 5% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)
133302313
235302212
337302112
438302111
540292010
64229199
74429198
84528188
94728177
104928177
115127166
125227156
135426155
145526145
155725144
165725144
175924134
186123133
196223123
206322123
216621112
226721102
236820102
24701992
25721891
26741781
27761671
28761671
29781561
30791461

Wind in September

Winds average 11 km/h in September.

Across September, daily wind ranges from about 11 km/h on the calmest days to 12 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
911calm
1011calm
1111calm
1211calm
1311calm
1411calm
1511calm
1611calm
1711calm
1811calm
1912calm
2012calm
2112calm
2212calm
2312calm
2412calm
2512calm
2612calm
2712calm
2812light breeze
2912light breeze
3012light 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 5:45 AM to 6:20 AM, and sunset from 6:50 PM to 5:54 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.15:456:50
213.05:466:48
313.05:476:46
412.95:486:44
512.95:506:43
612.85:516:41
712.85:526:39
812.75:536:37
912.75:546:35
1012.65:566:33
1112.65:576:31
1212.55:586:29
1312.55:596:27
1412.46:006:25
1512.46:026:23
1612.36:036:21
1712.36:046:19
1812.26:056:17
1912.16:076:15
2012.16:086:13
2112.06:096:11
2212.06:106:09
2311.96:116:07
2411.96:136:05
2511.86:146:04
2611.86:156:02
2711.76:166:00
2811.76:185:58
2911.66:195:56
3011.66:205:54

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 3.97 kWh/m².

For context, solar energy here swings from a low near 1.29 kWh/m² to a high of 6.22 kWh/m² in June across the year — September's 3.97 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.6Bright
24.6Bright
34.5Bright
44.5Bright
54.4Bright
64.4Bright
74.3Bright
84.3Bright
94.3Bright
104.2Bright
114.2Bright
124.1Bright
134.1Bright
144.0Bright
154.0Moderate
163.9Moderate
173.9Moderate
183.9Moderate
193.8Moderate
203.8Moderate
213.7Moderate
223.7Moderate
233.6Moderate
243.6Moderate
253.5Moderate
263.5Moderate
273.4Moderate
283.4Moderate
293.3Moderate
303.3Moderate
Planning a trip in September

Is September a good time to visit Orillia?

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

6.1
Sightseeing
4th-best month of the year
3.3
Beach & pool
4th-best month of the year

September is a reasonable time to visit Orillia for sightseeing.

What to pack for Orillia in September

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

In September, Orillia sees daytime highs around 20°C and nights near 11°C. Worth packing: rain gear. About 11 days see rain.

rain gear

Sea temperature near Orillia 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 56 km away) is warmest in August at about 21°C and coldest in March near 1°C.

It's comfortable for a long swim from Aug 9 to Aug 24 — about 0.5 months when the water holds above 20°C.

0°10°20°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarm
Sea temperature (°C)Comfort
Jan3Bracing
Feb2Bracing
Mar1Bracing
Apr2Bracing
May5Bracing
Jun11Bracing
Jul19Cool
Aug21Refreshing
Sep19Cool
Oct13Bracing
Nov9Bracing
Dec6Bracing

UV index in Orillia 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 Orillia 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 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 highHighModerateLowJun 20UV 8Jan 1UV 1
UV index (midday)Level
Jan1Low
Feb2Low
Mar3Moderate
Apr5High
May7High
Jun8Very high
Jul8Very high
Aug6High
Sep5High
Oct3Moderate
Nov2Low
Dec1Low

Air quality in Orillia 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 Orillia is worst in May — around 19 µg/m³ PM2.5 (moderate), about 2.1× the cleanest month (November, 9 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodMay 2019 µg/m³Nov 239 µg/m³
PM2.5 (µg/m³)Level
Jan11Good
Feb14Moderate
Mar16Moderate
Apr17Moderate
May19Moderate
Jun18Moderate
Jul18Moderate
Aug16Moderate
Sep14Moderate
Oct10Good
Nov9Good
Dec9Good
Location & terrain

Where is Orillia?

Orillia sits at 44.6°N, 79.4°W, 232 m above sea level, in Canada. The nearest listed city is Barrie, 30 km away.

Topography around Orillia

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

Within 3 km, the terrain around Orillia has only modest variations in elevation — a maximum elevation change of 87 m around an average of 239 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 203 m; within 80 km, significant variations in elevation — a maximum elevation change of 404 m.

The land around Orillia is covered by trees (32%), artificial surfaces (28%) and water (25%) within 3 km, trees (41%) and water (27%) within 16 km, and trees (54%) within 80 km.

3 km
87 m
16 km
203 m
80 km
404 m
treesgrasslandcroplandartificial surfacesbare terrainwaterwetland
September weather nearby: Barrie 30 km · Innisfil 39 km · Midland 40 km · Keswick 40 km · Bracebridge 48 km · Wasaga Beach 48 km · East Gwillimbury 56 km · Uxbridge 62 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 Orillia (44.6087°, -79.4207°, elevation 232 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).