Weather by Month in Ottawa

Ottawa experiences distinct seasons, with warm July days averaging 26°C / 78°F and cool January nights dropping to -14°C / 7°F. Rainfall averages 86 mm / 3.4 inches per month, with June typically the wettest. June offers the longest days with around 16 hours of daylight.

Monthly Climate Comparison

The biggest temperature swing occurs between March and April, as typical highs shift from 2.9°C / 37.2°F to 10.8°C / 51.5°F (about 7.9°C / 14.3°F).

Month Low Temperature High Temperature Category
January -13.9°C -4.8°C COLD
February -12.8°C -3°C COLD
March -6.8°C 2.9°C COLD
April 0.5°C 10.8°C COOL
May 7.8°C 18.6°C MILD
June 13.5°C 23.5°C WARM
July 16.5°C 25.8°C WARM
August 16.1°C 24.7°C WARM
September 12.3°C 20.8°C MILD
October 6°C 13.2°C COOL
November -0.6°C 5.7°C COLD
December -7.5°C -0.9°C COLD

Rain & Sunshine Patterns

Driest Months

#1 February
Best for: outdoor activities & sightseeing
#2 March
Best for: outdoor activities & sightseeing
#3 January
Best for: outdoor activities & sightseeing

Wettest Months

#1 June
Expect: possible showers, pack waterproofs
#2 July
Expect: possible showers, pack waterproofs
#3 August
Expect: possible showers, pack waterproofs

UV & Sun Protection Calendar

High UV Alert:
April, May, June, July, August require serious sun protection.
Jan
3
LOW-MOD
Feb
4
MODERATE
Mar
6
MODERATE
Apr
7
HIGH
May
7
HIGH
Jun
7
HIGH
Jul
7
HIGH
Aug
7
HIGH
Sep
6
MODERATE
Oct
5
MODERATE
Nov
3
LOW-MOD
Dec
2
LOW-MOD
Extreme (11+)
Avoid sun during midday, use SPF 50+
Very High (8-10)
Essential sun protection required
High (6-7)
Use SPF 30+, wear hat & sunglasses
Moderate (3-5)
Sun protection recommended
Low-Moderate (1-2)
Minimal protection needed
Low (0)
No protection required

Daylight Hours

Daylight varies from 8.8 hours in December (winter) to 15.6 hours in June (summer), which is a difference of 6.8 hours.

Shortest Days

December
8.8h
Average Sunrise:07:34
Average Sunset:16:21
Plan daytime activities for midday when light is best. Early sunsets mean evening plans should account for darkness.

Longest Days

June
15.6h
Average Sunrise:04:14
Average Sunset:19:51
Extended daylight perfect for evening activities and late dining. You can fit more sightseeing into each day.

Wind & Humidity Overview

Wind Conditions

Average wind speed
Windiest months:
April ( 12 km/h) March ( 12 km/h) November ( 12 km/h)
Packing tip: Conditions are generally calm, but a light layer is always handy.

Humidity Levels

Average humidity
73%
Most humid:
December ( 79%)
Least humid:
April ( 65%)
Packing tip: Choose breathable, natural fabrics like cotton or linen for comfort in humid conditions.

Seasonal Overview

Northern Hemisphere seasons shape the weather patterns throughout the year. Here's what to expect in each season:

Winter

January, February, December
Avg High
Avg Low
Avg Rain
Cold conditions; pack warm layers and waterproofs

Spring

March, April, May
Avg High
Avg Low
Avg Rain
Warming trend with frequent showers; pack waterproofs

Summer

June, July, August
Avg High
Avg Low
Avg Rain
Comfortable temperatures; enjoy outdoor activities

Autumn

September, October, November
Avg High
Avg Low
Avg Rain
Wet season begins; bring rain gear

Risk Ranking Table

Ranking Goal #1#2#3#4
Lowest rain risk
Feb 4 risk days
Jan 5 risk days
Mar 5 risk days
Aug 5 risk days
Lowest heatwave risk
Jan 0 risk days
Feb 0 risk days
Mar 0 risk days
Apr 0 risk days
Lowest cold risk
Jul 0 risk days
Aug 0 risk days
Jun 5 risk days
Sep 8 risk days
Lowest wind disruption risk
Aug 47 km/h
Jul 48 km/h
Sep 50 km/h
Jun 51 km/h
Most comfortable evenings
Aug 78 / 100
Jul 77 / 100
Jun 64 / 100
Sep 58 / 100
Best outdoor reliability
Feb 92 / 100
Aug 77 / 100
Jan 67 / 100
Dec 66 / 100

Monthly Details

Click any month for detailed weather information and packing advice.

Looking for the best time to visit?

Get personalized month rankings based on weather comfort, outdoor activity suitability, and seasonal conditions.

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Frequently Asked Questions

What is the best month to visit Ottawa?

The best months to visit Ottawa depend on your preferences. For warm weather, July is typically the warmest month. For dry conditions, February, March, January tend to have the least rainfall. Consider your priorities, and whether you prefer warmer temperatures, drier weather, or longer daylight hours.

When is Ottawa warmest?

July is typically the warmest month in Ottawa, with average high temperatures reaching around 26°C (79°F). This is peak summer weather, ideal for outdoor activities and sightseeing.

When is Ottawa coldest?

January is usually the coldest month, with average low temperatures dropping to around -14°C (7°F). Pack warm layers if visiting during this time, especially for evening activities.

When does Ottawa get the most rain?

June typically sees the most rainfall in Ottawa, averaging around 108mm (4.3 inches). It's wise to pack waterproof layers and have some indoor backup plans if you're visiting during this month.

What is the driest month in Ottawa?

February is typically the driest month, with average rainfall of just 59mm (2.3 inches). This makes it an excellent time for outdoor exploration and activities with minimal risk of rain disruption.

How much does the temperature vary in Ottawa throughout the year?

Temperatures in Ottawa range from average lows of 3°C (37°F) to highs of 11°C (53°F). This variation means you'll want to pack differently depending on when you visit, as layers are key for adapting to the seasonal changes.

Do I need sun protection when visiting Ottawa?

Yes, sun protection is important in Ottawa. UV levels can reach 7 during peak months, which is considered high. Pack sunscreen (SPF 30+), sunglasses, and a hat, especially if you'll be outdoors for extended periods.

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