Tomorrow's Weather Forecast - Ottawa

Tomorrow's weather in Ottawa. high 24°C (75°F), low 9°C (48°F). Overcast.

Tomorrow’s Outlook

Tomorrow will be 6°C warmer than today. Expect pleasant, mostly clear skies with little chance of rain. Humidity stays high near 80%, so it will feel muggier and stickier than the temperature alone suggests. A light breeze near 13 km/h is expected. Sunrise is at 6:37 AM and sunset at 7:19 PM, for about 12h 42m of daylight.

Tomorrow
24°/ 9°
Today18° / 8°

Tomorrow’s Hourly Weather Outlook

Morning6 AM – Noon13°
Rain probability
0%
Wind speed
9 km/h
AfternoonNoon – 6 PM22°
Rain probability
0%
Wind speed
13 km/h
Evening6 PM – Midn21°
Rain probability
3%
Wind speed
8 km/h
NightMidn – 6 AM11°
Rain probability
0%
Wind speed
6 km/h

24-Hour Rain & Temperature Forecast

Tomorrow12 Sep
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Temperature · peaks at +24°C

Planning Advice for Tomorrow

Clothing
Warm jacket and comfortable layers recommended.
Outdoor
Good conditions for outdoor activities.
Travel
Standard travel conditions expected.

Sunrise & Sunset

Sunrise
Dawn 6:07 AM
Total Daylight
Full day forecastSolar noon 12:58 PM
Sunset
Dusk 7:49 PM
vs today-3 min daylight
Sunrise shift1 min later
Sunset shift2 min earlier

5-Day Weather Forecast

Full 15-Day Forecast
Today11 Sep
Sunny
18°/ 8°
4–14
Wind
Tomorrow12 Sep
Overcast
24°/ 9°
3%
Rain
1–13
Wind
Sun13 Sep
Drizzle
24°/ 15°
50%
Rain
9–21
Wind
Mon14 Sep
Overcast
18°/ 9°
10%
Rain
2–15
Wind
Tue15 Sep
Drizzle
17°/ 7°
50%
Rain
1–17
Wind

Weather Insight

Ottawa is forecast to reach a high of 24°C tomorrow, with an overnight low around 9°C. That's 2° above the long-term average high of 22°C for this time of year. Expect little chance of rain (3% probability) and a gentle breeze averaging 13 km/h. Air quality is currently Moderate (AQI 53), driven mainly by PM2.5 at 9.7 μg/m³.

Today vs Normal

18°C-4° below normal

The long-term average high for today is 22°C.

7 of the last 28 days with published data ran above normal.

It continues that pattern - today's forecast is also running below normal.

2026-08-28: 19°C19°2026-08-29: 21°C21°2026-08-30: 22°C22°2026-08-31: 24°C24°2026-09-01: 20°C20°2026-09-02: 22°C22°2026-09-03: 25°C25°2026-09-04: 23°C23°2026-09-05: 22°C22°2026-09-06: 22°C22°2026-09-07: 23°C23°2026-09-08: 23°C23°

Red = above normal, blue = at or below · last 12 days

Air Quality

Air Quality
Moderate

Air quality is acceptable for most people. Unusually sensitive individuals should consider reducing prolonged or heavy outdoor exertion.