August weather forecast and climate
Ottawa, Canada

A view of The Parliament Hill from the Ottawa River in Ottawa, Canada
A view of The Parliament Hill from the Ottawa River in Ottawa, Canada
The last month of the summer, August, is also a moderately hot month in Ottawa, Canada, with average temperature fluctuating between 13.7°C (56.7°F) and 24°C (75.2°F).

Temperature

In Ottawa, the average high-temperature is almost the same as in July - a still moderately hot 24°C (75.2°F). In August, in Ottawa, the average low-temperature is 13.7°C (56.7°F).

Humidity

In Ottawa, the average relative humidity is 81%.

Rainfall

In August, in Ottawa, the rain falls for 15.9 days. Throughout August, 68mm (2.68") of precipitation is accumulated. Throughout the year, in Ottawa, there are 149.6 rainfall days, and 772mm (30.39") of precipitation is accumulated.

Snowfall

June through September are months without snowfall.

Daylight

In August, the average length of the day in Ottawa is 14h.

Sunshine

In Ottawa, the average sunshine in August is 9.9h.

UV index

Months with the highest UV index are June through August, with an average maximum UV index of 5. A UV Index value of 3 to 5 symbolizes a moderate threat to health from unsafe exposure to the UV radiation for the average person.
Note: The daily maximum UV index of 5 in August interpret into the following advice:
Take precautions - Protection against sunburn is recommended. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.

What is the temperature in August in Ottawa?

In Ottawa, in August, the average high-temperature is 24°C (75.2°F), and the average low-temperature is 13.7°C (56.7°F).

What is the average humidity in August in Ottawa?

In August, the average relative humidity is 81%.

How much does it rain in Ottawa in August?

In Ottawa, Canada, in August, it is raining for 15.9 days, with typically 68mm (2.68") of accumulated precipitation.

When it does not snow in Ottawa?

In Ottawa, Canada, snow does not fall in June through September.

What is the average length of the day in August in Ottawa?

In August, the average length of the day is 14h.

How many hours of sunshine does Ottawa have in August?

In August, the average sunshine in Ottawa, Canada, is 9.9h.

When is the highest UV index in Ottawa?

June through August, with an average maximum UV index of 5, are months with the highest UV index.

How high is the UV index in August in Ottawa?

In August, the average daily maximum UV index is 5. A UV Index value of 3 to 5 symbolizes a moderate health threat from unprotected exposure to the UV radiation.
Average temperature in August - Ottawa, Canada
  • Average high temperature in August: 24°C

The warmest month (with the highest average high temperature) is July (25.3°C).
The month with the lowest average high temperature is January (-6.3°C).

  • Average low temperature in August: 13.7°C

The month with the highest average low temperature is July (14.5°C).
The coldest month (with the lowest average low temperature) is January (-14.5°C).

Average humidity in August - Ottawa, Canada
  • Average humidity in August: 81%

Months with the highest relative humidity are January and February (91%).
The month with the lowest relative humidity is May (77%).

Average rainfall in August - Ottawa, Canada
  • Average rainfall in August: 68mm

The wettest month (with the highest rainfall) is October (78mm).
The driest month (with the least rainfall) is September (54mm).

Average rainfall days in August - Ottawa, Canada
  • Average rainfall days in August: 15.9 days

The month with the highest number of rainy days is July (17.1 days).
The month with the least rainy days is February (5.9 days).

Average snowfall in August - Ottawa, Canada
  • Average snowfall in August: 0mm

The month with the highest snowfall is January (321mm).
Months with the least snowfall are June, July, August and September (0mm).

Average snowfall days in August - Ottawa, Canada
  • Average snowfall days in August: 0 days

The month with the highest number of snowfall days is January (19.8 days).
Months with the least snowfall days are June, July, August and September (0 days).

Average daylight in August / Average sunshine in August - Ottawa, Canada
  • Average daylight in August: 14h

The month with the longest days is June (Average daylight: 15.6h).
The month with the shortest days is December (Average daylight: 8.8h).

  • Average sunshine in August: 9.9h

The month with the most sunshine is July (Average sunshine: 10.2h).
The month with the least sunshine is February (Average sunshine: 2.8h).

Average UV index in August - Ottawa, Canada
  • Average UV index in August: 5

Months with the highest UV index are June, July and August (UV index 5).
Months with the lowest UV index are January, February, November and December (UV index 1).