Calgary records about 419mm of rain across roughly 73 wet days a year, which is a 20% chance on an average day. June is the wettest month at 80mm (19% of the annual total) and February the driest at 10mm. Local rain type: brief showers. Calgary is surprisingly dry for a mountain-adjacent city. Summer storms build over the Rockies and sweep across the prairies — dramatic but brief.
Chance of rain on an average day: 20%
Rainfall climatology for Calgary. The live hour-by-hour answer for today loads at the top of this page from Open-Meteo and refreshes through the day — the figures below describe a typical year, not today.
Last updated: · Live forecast data refreshes hourly.
| Annual rainfall | 419mm |
| Rain days per year | 73 |
| Odds on an average day | 20% |
| Wettest month | June — 80mm over 15 days |
| Driest month | February — 10mm over 2 days |
| Rain type | brief showers |
| Best dry window | September offers dry, warm Indian summer conditions with stunning Rocky Mountain views. |
| Worst rain window | June brings the most rainfall, often as dramatic afternoon thunderstorms from the mountains. |
June delivers 700% more rain than February (80mm vs 10mm). That gap is the difference between planning around showers and ignoring them.
No single month holds more than 19% of the annual total, so rain in Calgary is spread through the year — there is no season you can rely on being dry.
Calgary rain typically comes as discrete showers, so a compact umbrella and a flexible plan are usually enough.
Rain falls on about 15 days in June against 2 in February — the frequency swing matters more for planning than the millimetre totals.
Climate normals. Use them to judge whether today's live forecast at the top of the page is typical or unusual for the season.
| Month | Rainfall | Rain days | Chance on a given day | Highs |
|---|---|---|---|---|
| January | 12mm | 2 | 7% | -3°C |
| February | 10mm | 2 | 7% | -3°C |
| March | 18mm | 3 | 10% | 1°C |
| April | 28mm | 5 | 17% | 7°C |
| May | 57mm | 11 | 37% | 13°C |
| June | 80mm | 15 | 50% | 19°C |
| July | 55mm | 11 | 37% | 23°C |
| August | 42mm | 8 | 27% | 23°C |
| September | 36mm | 7 | 23% | 19°C |
| October | 17mm | 3 | 10% | 13°C |
| November | 13mm | 2 | 7% | 7°C |
| December | 14mm | 3 | 10% | 1°C |
Rain probability is the chance that at least 0.2mm falls at your location — not how long it rains. For Calgary we combine the hourly probability curve, expected volume in millimetres, and the city's own rainfall record into a single umbrella verdict.
| Factor | Weight | What it measures |
|---|---|---|
| Hourly probability | 40% | Peak and sustained chance of measurable rain across the next 24 hours. |
| Expected volume | 30% | Total millimetres, which separates a passing shower from a genuine soaking. |
| Timing & duration | 20% | When rain starts, when it eases, and the longest continuous dry window. |
| Local rain type | 10% | Drizzle, brief showers, thunderstorms or monsoon — each needs different gear. |
Live hourly values come from Open-Meteo and refresh through the day. Monthly rainfall figures are climate normals, so they describe a typical year rather than a forecast.
Calgary records rain on roughly 73 days a year — about a 20% chance on any given day — totalling around 419mm.
June, with about 80mm over 15 rain days. That is 19% of the entire year's rainfall in a single month.
February is the driest month at 10mm across roughly 2 days. September offers dry, warm Indian summer conditions with stunning Rocky Mountain views.
Calgary is surprisingly dry for a mountain-adjacent city. Summer storms build over the Rockies and sweep across the prairies — dramatic but brief.
No. Probability is the chance that at least 0.2mm of rain falls at your location at some point in the period. Check the expected millimetres alongside it: 40% with 0.4mm is a passing shower, 40% with 12mm is a soaking.