Oshawa in Summer
In summer (June, July and August), Oshawa sees average daytime highs around 25°C and overnight lows near 15°C, with 252 mm of rain over about 32 wet days across the season. It is the warmest season of the year and the wettest season of the year.
Over the season highs climb from about 21°C in early June to 24°C by late August. The sky is clear or mostly clear about 31% of the time across summer, and the air most often feels dry.
Summer is Oshawa's best season of the year to visit on our travel score. For the whole year in context, see Oshawa's year-round climate.
- Avg daytime high
- 25°C
- warmest season of the year
- Avg overnight low
- 15°C
- Rainfall
- 252 mm
- 32 wet days
- Avg wind
- 11 km/h
- Travel score
- 6.7
- best season of the year
- Months
- Jun · Jul · Aug
Temperature in Oshawa in Summer
Over the season highs climb from about 21°C in early June to 24°C by late August.
A typical summer day in Oshawa reaches about 25°C and drops to 15°C overnight. The warmest of the three months is July, the coolest June.
How summer really feels in Oshawa
Once humidity and wind are folded in, summer brings about 0 days that feel above 32°C and 0 that feel at or below 0°C.
summer sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.
Oshawa weather by month
How the three summer months (June, July and August) compare with the rest of the year — the season's months are highlighted.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Snow days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|---|
| Jan | -2° / -10° | 65 | 10.7 | 8.8 | 9.1 | 0.0 |
| Feb | -1° / -10° | 51 | 8.2 | 6.7 | 10.2 | 0.0 |
| Mar | 4° / -5° | 60 | 10.4 | 5.5 | 11.6 | 0.2 |
| Apr | 11° / 2° | 83 | 11.3 | 2 | 13.2 | 2.8 |
| May | 18° / 8° | 76 | 11 | 0 | 14.5 | 5.6 |
| Jun | 23° / 14° | 89 | 11 | 0 | 15.2 | 6.6 |
| Jul | 26° / 16° | 84 | 10.5 | 0 | 14.9 | 6.6 |
| Aug | 25° / 15° | 80 | 10.1 | 0 | 13.8 | 6.9 |
| Sep | 21° / 11° | 80 | 9.1 | 0 | 12.3 | 6.6 |
| Oct | 14° / 5° | 83 | 11.4 | 0.2 | 10.8 | 3.8 |
| Nov | 7° / -0° | 73 | 10.2 | 2.7 | 9.5 | 0.8 |
| Dec | 1° / -6° | 67 | 10.6 | 6.8 | 8.8 | 0.0 |
Cloud cover in Summer
The sky is clear or mostly clear about 31% of the time across summer.
Chance of precipitation in Summer
Oshawa gets around 252 mm of rain over 32 wet days across summer. The line is the day-by-day chance of measurable precipitation.
Humidity in Summer
Most of summer feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Summer
Winds average 11 km/h across summer.
Sunrise & sunset in Summer
Daylight runs from about 15 hours in early June to 13 h 06 min by late August. The lit band spans sunrise to sunset each day.
Solar energy in Summer
Average shortwave solar energy reaching the ground each day across summer, about 6.1 kWh/m².
Is summer a good time to visit Oshawa?
Our two travel scores rate summer for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
summer is a reasonable time to visit Oshawa for sightseeing.
What to pack for Oshawa in Summer
From summer's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In summer, Oshawa sees daytime highs around 25°C and nights near 15°C. Pack sun protection. Worth having: light clothes and rain gear. About 32 days see rain.
Sea temperature near Oshawa in Summer
The nearest coast averages about 18°C across summer — the other half of the beach question. The full-year curve and swim-comfort zones are below.
The sea offshore is warmest in August at about 21°C and coldest in March near 3°C.
It's comfortable for a long swim from Jul 27 to Sep 2 — about 1.2 months when the water holds above 20°C.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sea temperature (°C) | 4 | 3 | 3 | 4 | 7 | 14 | 19 | 21 | 19 | 13 | 8 | 5 |
| Comfort | Bracing | Bracing | Bracing | Bracing | Bracing | Bracing | Cool | Refreshing | Cool | Bracing | Bracing | Bracing |
| Sea temperature (°C) | Comfort | |
|---|---|---|
| Jan | 4 | Bracing |
| Feb | 3 | Bracing |
| Mar | 3 | Bracing |
| Apr | 4 | Bracing |
| May | 7 | Bracing |
| Jun | 14 | Bracing |
| Jul | 19 | Cool |
| Aug | 21 | Refreshing |
| Sep | 19 | Cool |
| Oct | 13 | Bracing |
| Nov | 8 | Bracing |
| Dec | 5 | Bracing |
UV index in Oshawa in Summer
Clear-sky midday UV across summer averages around 7 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Oshawa peaks around June 20 at about 8 (very high) — sunscreen and a hat are worth it in the middle of the day. It bottoms out near December 21 at about 1 (low).
The index reaches 3 or more — the level where the WHO recommends sun protection — in 7 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 1 | 2 | 4 | 5 | 6 | 8 | 7 | 6 | 5 | 3 | 2 | 1 |
| Level | Low | Low | Moderate | High | High | Very high | Very high | High | High | Moderate | Low | Low |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 1 | Low |
| Feb | 2 | Low |
| Mar | 4 | Moderate |
| Apr | 5 | High |
| May | 6 | High |
| Jun | 8 | Very high |
| Jul | 7 | Very high |
| Aug | 6 | High |
| Sep | 5 | High |
| Oct | 3 | Moderate |
| Nov | 2 | Low |
| Dec | 1 | Low |
Where is Oshawa?
Oshawa sits at 43.9°N, 78.8°W, 105 m above sea level, in Canada. The nearest listed city is Whitby, 7.0 km away.
Topography around Oshawa
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Oshawa.
Within 3 km, the terrain around Oshawa has only modest variations in elevation — a maximum elevation change of 85 m around an average of 111 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 346 m; within 80 km, significant variations in elevation — a maximum elevation change of 394 m.
The land around Oshawa is covered by artificial surfaces (52%) and trees (35%) within 3 km, water (31%) and trees (22%) within 16 km, and water (42%) and trees (24%) within 80 km.
Canada travel facts
- Travel advisory
- Level 1
- Exercise Normal Precautions
- Power plugs
- Type A / B
- 120 V · 60 Hz
- Prices
- ≈ 83% of US
- price level, 2025
- GDP per capita
- $55,698
- 2025
- Happiness
- 6.7 / 10
- World Happiness, 2025
- Safe drinking water
- 97%
- of population, 2024
- Homicide rate
- 2
- per 100k, 2023
- Road deaths
- 5.3
- per 100k/yr, 2019
- Income group
- High
- World Bank
- Religion
Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.
Data sources
Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Oshawa (43.9001°, -78.8496°, elevation 105 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google.