Ottawa weather in August 2026

Expect daytime maximum temperatures of 25°C in Ottawa, Ontario in August based on long-term weather averages. There are 8 hours of sunshine per day on average with 11 days with some rainfall and typically 86 mm of rainfall in the month.

  • 25°C maximum daytime temperature in August in Ottawa25
    25°C max day temperature
  • 8 hours of sunshine per day
  • 11 days with some rainfall in August in Ottawa11
    11 days with some rainfall
  • 14°C minimum night-time temperature in August in Ottawa14
    14°C min night temperature
  • 14 hours of daylight per day in August in Ottawa14
    14 hours of daylight per day
  • No heat & humidity in August in Ottawa0
    No heat & humidity
  • 86 mm monthly rainfall in August in Ottawa86
    86 mm of monthly rainfall
  • UV (maximum) index 7 (High) in August in Ottawa7
    7 (High) UV index

More about Ottawa

Ottawa by month

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

Recommended for Ontario

Green Motion: up to 25% off with loyalty programme

  • Become a Green Motion loyalty member for FREE
  • Save up to 25% on future car rentals + extra offers
  • Discount varies by membership tier & number of rentals
Go to Green Motion deal >>

View all Green Motion offers

The August weather guide for Ontario (Ottawa) shows long term weather averages processed from data supplied by CRU (University of East Anglia), the Met Office & the Netherlands Meteorological Institute. Find out more about our data sources.

Metric (°C / mm)  |  Imperial (°F / inches)

Back to top

More about Ontario

How hot is it in Ottawa in August?

Daytime temperatures usually reach 25°C in Ottawa in August with low heat and humidity, falling to 15°C at night.

How sunny is it in Ottawa in August?

There are normally 8 hours of bright sunshine each day in Ottawa in August - that's 56% of daylight hours.

How warm is the sea around Ottawa in August?

The average sea temperature around Ottawa in August is 21°C.

Does it rain in Ottawa in August?

There are usually 10 days with some rain in Ottawa in August and the average monthly rainfall is 83mm.

Ottawa August sunrise & sunset times

Browse the sunrise and sunset times for Ottawa in August 2026. Select a month to view Ottawa sunrise and sunset times for the next 12 months.

JanFebMarAprMayJunJulAugSepOctNovDec

Date Sunrise times Sunset times
Saturday, 1st August 2026 04:47 19:30
Sunday, 16th August 2026 05:05 19:08
Monday, 31st August 2026 05:23 18:42

Related posts

Popular travel offers

Explore holiday destinations

More holidays

Save with latest deals & discounts

More deals

Airport parking

More parking

Airport lounges

More lounges

Top ^