July in Calgary is a bit of a trickster. You wake up to a crisp morning that feels more like early autumn, but by 3:00 PM, you’re looking for a patio with a heavy-duty misting fan. It's the hottest month in this high-altitude city, yet it’s also the time when locals carry a "just-in-case" hoodie everywhere they go. Honestly, if you don't like the weather here, just wait ten minutes.
Most people expect a steady, predictable heat when they look up the temperature in Calgary in July. What they get is a rollercoaster. We’re talking about a place where the sun sets around 10:00 PM, giving you massive amounts of daylight, but the moment that sun dips behind the Rockies, the mercury crashes.
The Reality of the Numbers
On paper, the stats look pretty tame. Environment and Climate Change Canada (ECCC) typically puts the average daily high for July around 23°C to 24°C (73°F to 75°F). That sounds like the "Goldilocks" of weather—not too hot, not too cold. But averages are liars.
In recent years, we've seen 2024 throw a curveball with a nine-day heatwave where temperatures stayed above 29°C, shattering old records. Then you look at July 2025, which felt like a totally different planet. Calgary actually recorded its coldest July 27th in over 90 years that summer, with a high that barely scraped 16.1°C.
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What a Typical July Day Looks Like
- Morning (6:00 AM - 9:00 AM): It's often around 9°C to 12°C. You'll see joggers in leggings and light jackets.
- Mid-Day (11:00 AM - 2:00 PM): The dry heat starts to kick in. This is when the temperature in Calgary in July starts to feel real. Because the air is so dry, 25°C feels much hotter than it does in Toronto or Vancouver.
- Afternoon Peak: This is the danger zone for sunburns. Calgary is sitting at about 1,048 meters above sea level. You are closer to the sun here, and the UV index regularly hits "Very High" or "Extreme."
- Late Evening: Once the sun sets (usually around 9:45 PM or 10:00 PM), the temperature plummets. It’s not uncommon for it to drop 15 degrees in a few hours.
Thunderstorms and the "Hail Alley" Factor
You can't talk about July temperatures without talking about the clouds. Calgary sits right in the middle of what meteorologists call "Hail Alley." When the hot, dry air from the prairies hits the cool, moist air flowing over the mountains, things get violent.
July is actually one of Calgary's wettest months. We aren't talking about grey, drizzly London rain, though. It’s usually a massive, theatrical thunderstorm that rolls in around 5:00 PM, drops a month's worth of rain (and sometimes golf-ball-sized hail) in twenty minutes, and then leaves the sky perfectly blue again.
In 2025, the city saw nearly double its normal rainfall by mid-July. These storms don't just soak you; they act like a natural air conditioner. A storm can instantly knock the temperature in Calgary in July down from a sweltering 30°C to a shivering 14°C.
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The Wildfire Smoke Wildcard
This is the part nobody likes to talk about, but it's the reality of living in Western Canada now. In July, the temperature is often dictated by the "smoke layer." If there are wildfires in British Columbia or Northern Alberta, the smoke drifts into the Bow Valley and sits over the city like a hazy lid.
This creates a weird, "apocalyptic" heat. The sun looks like a dim red coin, and while the smoke might actually block some of the direct heat, it traps the warmth near the ground. It makes the air feel heavy and "chewy." If you're visiting in July, checking the Air Quality Health Index (AQHI) is just as important as checking the thermometer.
Humidity (Or the Lack Thereof)
Calgary is semi-arid. If you're coming from the East Coast or the Southern US, the lack of humidity will be the first thing you notice. Your hair will behave, but your skin will feel like parchment paper.
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Because the humidity stays low (often below 50% during the day), your sweat actually evaporates the way it’s supposed to. This makes even 30°C feel manageable compared to the "swamp-heat" of Montreal or New York. However, it also means you get dehydrated way faster than you realize.
How to Handle the Temperature in Calgary in July
If you’re planning a trip for the Calgary Stampede or a hike in the nearby Rockies, don't trust a single-day forecast. You basically have to pack for three different climates.
- Hydrate like it's your job. The combination of high altitude and dry air means you're losing water just by breathing.
- Layers are non-negotiable. A t-shirt for the afternoon, a flannel or light sweater for the evening, and a waterproof shell for the inevitable 6:00 PM thunderstorm.
- Invest in high-SPF sunscreen. That high-altitude sun is no joke. You can get a nasty burn even when the air feels "mildly cool."
- Check the radar. Use an app with a good local radar to see if those dark clouds over the mountains are heading your way. If they look green or extra dark, seek cover—hail is likely.
The temperature in Calgary in July is a wild mix of intense prairie sun and mountain-cooled breezes. It’s rarely boring, occasionally intense, and always demands your respect.
Actionable Advice for Your Visit
Download a reliable weather app like WeatherCan (the official ECCC app) and pay attention to the "Humidex" and "Wind Chill" markers, even in summer. If you are heading into the mountains, remember that temperatures at Moraine Lake or Johnston Canyon will be 5–8 degrees cooler than downtown Calgary. Keep a liter of water and a spare jacket in your car or backpack at all times.