Best time to visit Ottawa

Re-score for me — drag the dial — every chart on the page recolours live for your heat limit 27°C
I'm comfortable up to 27°C feels-like
22° heat-averse 30° heat-loving

Default 27 °C is the upper edge of the Holiday Climate Index "ideal comfort" band (Scott, Rutty, Amelung & Tang, 2016). Above this, most warm-tourism travellers report measurable discomfort.

Saved to this browser. Changes update the strips below.
Recent · 2020-2024
Interest Google Trends 2021-2025 searches, not arrivals (?)
Day · avg daily high (?)
Night · avg overnight low (?)
UV index · On a typical day around midday, UV is about this (?)
123455654211
On the sunniest 1 in 10 days, UV reaches this — and even higher
4677874
PM2.5 air quality · on a typical day (?)
58889151298655
On the worst 1 in 10 days, PM2.5 reaches this — and even higher
101515131527181614101012
September 9/10 feels 21°C (+1°C vs 1991-2020) · HCI 87/100
Day 21° · Night 13° 63% humidity 14 km/h wind 8 rain days (88h) 214h sun
Thermal 9
Sky 9
Rain 8
Wind 10

Higher = better, including rain & wind (green = "doesn't hurt the score", not "lots of it").

Compare with another destination

Add as many as you like — stacked below the main strips above. Each row is just the recent-window score strip and (for beach destinations) sea-temperature strip.

Tours in Ottawa

8 top-rated tours via Viator. Booking links earn this site a commission at no cost to you. Map locations are approximate (centred on Ottawa).

  1. 1Ottawa City Tour by Land and Water4.22★ (610)1hfrom $44🔥 Selling fast
  2. 2Lilo Floating Tiki Bar on the Ottawa River4.80★ (71)1h 30mfrom $63🔥 Selling fast
  3. 3Ottawa Food Tour with ByWard Market Flavors & 6 Local Tastings5.00★ (19)3hfrom $88🔥 Selling fast
  4. 4Ghosts of the Bytown Museum5.00★ (2)1h 15mfrom $28🔥 Selling fast
  5. 5Moana Floating Tiki Bar on the Ottawa River5.00★ (1)1h 30mfrom $63🔥 Selling fast
  6. 6Haunted Walk's Nightmare Before (and after) Christmas Tour in Ottawa5.00★ (2)1h 15mfrom $25🔥 Selling fast
  7. 7Ottawa Boat Cruise - Rideau Canal Cruise4.28★ (1,151)1h 30mfrom $42🔥 Selling fast
  8. 8Petite Nation Wine & Cider Tour - Day Trip From Ottawa & Gatineau5.00★ (15)8hfrom $139🔥 Selling fast

Last refreshed 2026-05-30.

Similar climatesMontreal97% · Quebec City92% · Niagara Falls92%

Other destinations with the most-alike year-round climate to Ottawa (apparent temperature, rain hours, sunshine — matched within the same trip-profile). The ±N chip compares each match's typical score for the current month against Ottawa's. Based on the 2020-2024 climatology, not this year's actual weather.

Month-by-month

Month Temp °C Feels °C Rain days Rain h Rain h/day Humidity Wind km/h Sun h UV Interest Score
Jan -12–-3 -8 10 144 14.4 68% 16 109 1 Quiet 3
Feb -12–-1 -6 11 135 12.3 63% 17 131 2 Quiet 4
Mar -5–5 0 11 140 12.7 57% 18 173 3 Quiet 4
Apr 1–12 8 12 143 11.9 54% 19 185 4 Quiet 5
May 8–20 17 10 101 10.1 50% 16 252 5 Quiet 8
Jun 14–24 24 14 137 9.8 57% 16 244 5 Quiet 8
Jul 17–26 28 14 126 9.0 60% 15 274 6 Quiet 8
Aug 17–25 26 14 145 10.4 64% 14 247 5 Peak 7
Sep 13–21 21 8 88 11.0 63% 14 214 4 Busy 9
Oct 7–15 13 11 134 12.2 67% 16 153 2 Moderate 6
Nov 0–7 3 11 112 10.2 66% 18 122 1 Peak 4
Dec -6–1 -4 14 183 13.1 72% 17 78 1 Busy 3

UV Index in Ottawa by Month

UV index in Ottawa peaks at 6 (high) in July, dropping to 1 (low) in December. July have high UV — SPF 30+ and sunglasses recommended.

Best months in detail

September

9/10

13–21°C · 8 rain days (88h) · 214 sun hours · 63% humidity · Busy crowd · UV 4 (moderate)

May

8/10

8–20°C (feels 17°C) · 10 rain days (101h) · 252 sun hours · 50% humidity · Quiet crowd · UV 5 (moderate) · sunniest 1 in 10 days reach 7 (high)

June

8/10

14–24°C · 14 rain days (137h) · 244 sun hours · 57% humidity · Quiet crowd · UV 5 (moderate) · sunniest 1 in 10 days reach 7 (high)

Every month

Show the other 9 months in detail

January

3/10

-12–-3°C (feels -8°C) · 10 rain days (144h) · 109 sun hours · 68% humidity · Quiet crowd · UV 1 (low)

February

4/10

-12–-1°C (feels -6°C) · 11 rain days (135h) · 131 sun hours · 63% humidity · Quiet crowd · UV 2 (low)

March

4/10

-5–5°C (feels 0°C) · 11 rain days (140h) · 173 sun hours · 57% humidity · Quiet crowd · UV 3 (low) · sunniest 1 in 10 days reach 4 (moderate)

April

5/10

1–12°C (feels 8°C) · 12 rain days (143h) · 185 sun hours · 54% humidity · Quiet crowd · UV 4 (moderate) · sunniest 1 in 10 days reach 6 (moderate)

July

8/10

17–26°C (feels 28°C) · 14 rain days (126h) · 274 sun hours · 60% humidity · Quiet crowd · UV 6 (high) · sunniest 1 in 10 days reach 8 (high)

August

7/10

17–25°C (feels 26°C) · 14 rain days (145h) · 247 sun hours · 64% humidity · Peak crowd · UV 5 (moderate) · sunniest 1 in 10 days reach 7 (high)

October

6/10

7–15°C (feels 13°C) · 11 rain days (134h) · 153 sun hours · 67% humidity · Moderate crowd · UV 2 (low) · sunniest 1 in 10 days reach 4 (moderate)

November

4/10

0–7°C (feels 3°C) · 11 rain days (112h) · 122 sun hours · 66% humidity · Peak crowd · UV 1 (low)

December

3/10

-6–1°C (feels -4°C) · 14 rain days (183h) · 78 sun hours · 72% humidity · Busy crowd · UV 1 (low)

Frequently asked questions about visiting Ottawa

When is the best time to visit Ottawa?

September is the highest-scoring month (9/10 on the Holiday Climate Index). Typical conditions: 13–21°C (8 rainy days). The top three months by score are September, May, June.

What is the worst time to visit Ottawa?

December is the lowest-scoring month (3/10). Typical conditions: -6–1°C (14 rainy days).

Is Ottawa too cold in winter?

2 months (January, February) cross our cold deal-breaker (apparent temperature below the cap). Doable with the right gear, but expect the climate score to be held down by the gate.

When are crowds lowest in Ottawa?

Search-interest seasonality (Google Trends 2021-2025) is lowest in May and peaks in August. Interest tracks both in-trip visitors and lead-time planners, so treat it as a "destination is on people's minds" signal rather than literal arrivals.

Which months in Ottawa have good weather but fewer tourists?

May (climate 8/10, crowd index 0) and June (climate 8/10, crowd index 14) — shoulder months with above-average climate and below-median search-interest. Often the best value-for-weather trade.

What is the UV index in Ottawa by month?

UV peaks at 6 (high) in July and is lowest in December at 1 (low). Monthly peak values: Jan 1, Feb 2, Mar 3, Apr 4, May 5, Jun 5, Jul 6, Aug 5, Sep 4, Oct 2, Nov 1, Dec 1.

What is the UV index in Ottawa in July?

July is the peak UV month in Ottawa, with a daily-peak UV index of 6 (high). Apply SPF 30+, wear sunglasses, and seek shade during midday hours.

How high can UV get in Ottawa on the sunniest days?

Most days look like the monthly average, but on the sunniest ~1 in 10 days UV climbs higher than the mean suggests. July is the worst case: typical days average UV 6 (high), but the top 10% of days reach UV 8 (high) — and even higher. Months where the sunniest days routinely exceed the typical reading: March, April, May, June, July, August, October. Plan sun protection for the worst case, not the average.

Is air quality in Ottawa bad for travelers?

PM2.5 (fine-particle pollution) exceeds the WHO sensitive-group guideline (15 µg/m³) in 4 months: March, June, July, August. The worst month is June with a typical-day mean of 15 µg/m³ (moderate); on the worst 10% of days PM2.5 reaches 27 µg/m³ (unhealthy) and higher. People with asthma, heart conditions, or sensitive children may want to avoid these months or limit outdoor activity. Source: CAMS via Open-Meteo.