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Calgary weather by month: averages, rainfall & climate trends

Set in the Rocky Mountain foothills, Calgary is a sunny, dry-aired prairie city famous for its chinooks (warm mountain winds that can melt a deep winter freeze in hours) and for weather that changes on a whim. Calgary weather by month: average temperatures, rainfall, extremes and how the climate has changed since 1940.

Today vs average

+0.4°Chigh near average

13° / 0°Today
12° / 1°Average
see today in detail →

How it's changed

+1.4°Caverage temperature, 2016–2025 vs 1940–1949average temperature vs 1940–49173frost days a year now (2016–2025) · 188 in the 1940sfrost days a year · 188 in the 1940s14days above 30°C a year now (2016–2025) · 3 in the 1940sdays above 30°C · 3 in the 1940s+1.4°C vs the 1940s · see how it's changed →
Weather by montha typical year, averaged over the full recordJanuary, rain 18 mmhigh −4°low −13°February, rain 18 mmhigh 0°low −11°March, rain 26 mmhigh 4°low −7°April, rain 41 mmhigh 12°low −1°May, rain 75 mmhigh 17°low 4°June, rain 99 mmhigh 21°low 8°July, rain 69 mmhigh 24°low 10°August, rain 63 mmhigh 24°low 9°September, rain 47 mmhigh 19°low 5°October, rain 28 mmhigh 12°low 0°November, rain 22 mmhigh 3°low −7°December, rain 19 mmhigh −2°low −11°wettest month June, 99 mm · 526 mm a yearsee month by month →

Right now

What it's doing today vs the historical average for this date.
Mostly clear

Right now

5.9°

2°feels like
38%humidity
−7°dew point
7 km/hfrom E
UV index0.0
sunrise08:05sunset18:37day length10h 32m
SunClear13°0°
TodayOvercast13°1°
TueOvercast10°1°
WedClear17°3°
ThuClear15°7°
FriOvercast10°1°
SatOvercast4°−1°

On this date: October 19

Today (forecast)
13° / 0°
Average for October 19
12° / 1°

High near average · +0.4°C

  • Highest since 1940: 25.2° · 2022
  • Lowest since 1940: −13.4° · 1949
  • One year ago: 13° / 4°

Every October 19 in history, coldest to hottest

▲ Daily highs▼ Daily lows

Dots show daily highs (top) and lows (bottom) for each October 19 on record (n = 87). Outlined dots are today's forecast.

Area we sample

Each city's history comes from one ERA5 grid cell, about 28 km across, shown by the dashed box. Near mountains or coasts, conditions can vary across the cell.

Location & data

Historical weather for Calgary is sampled from the ECMWF ERA5 reanalysis at 51.05°N, 114.09°W, with daily records since 1940.

Coordinates
51.05°N, 114.09°W
Time zone
America/Edmonton
Period
1940–2026
Data source
ERA5 (ECMWF)

Last 30 days

23 of the last 31 days were warmer than the historical average for that date. Average difference: +1.8°C.

Each bar is one day, from morning low to afternoon high. Warm-colored bars are days whose mean ran above average; cool bars ran below. The dot inside the bar is the daily mean. The shaded band is the typical 10–90% range expected for that date. Average = the day's mean temperature averaged across every year of record (1940–2026) for that calendar date.

This date over the years

One dot per year, showing the mean temperature on this calendar date. Dots are warmer or cooler than the long-term average (dashed line); the shaded band is the typical 10–90% range, and the highlighted dot is today's forecast. Based on ERA5 reanalysis: modelled estimates, not station readings.

Weather by month

Average temperatures and rainfall for each month: a typical year, from the full record.

Climate overview

Calgary has a humid continental climate (Köppen Dwb) shaped by its high elevation in the foothills of the Canadian Rockies. Its winters are cold and dry but famously variable: bitterly cold spells can be transformed within hours by warm, dry chinook winds spilling east over the mountains, which can lift the temperature by twenty degrees or more in a single afternoon. The air is dry and the city sunny, with relatively little precipitation.

The mountains keep the weather unpredictable in every season: it can snow as late as June. Summer is the wetter, stormier time of year, and in June 2013 severe flooding on the Bow and Elbow rivers forced the evacuation of tens of thousands of residents in one of the costliest disasters in Canadian history.

The warmest month is July, with typical afternoon highs of 24.2°C and nights around 10.2°C. At the other extreme, January brings afternoon highs of about −3.5°C and typical overnight lows of −13.3°C. Around 175 days a year dip below freezing.

In total, Calgary averages about 526 mm of precipitation a year; June is usually the wettest month (99 mm) and January the driest (18 mm).

Comparing the record's first decade with its most recent one, Calgary now averages 1.4°C warmer than it did in the 1940s. The count of days past 30°C has risen from roughly 3 a year to 14 between the record's first and last decades.

Sources:en.wikipedia.orgbritannica.comweather.gc.ca

Climate graph (climograph)

July is the warmest month, January the coolest: a yearly swing of 26°C. Wettest month: June (~99 mm). Whole year averages ~526 mm of rain.

Bars = average monthly rainfall (right axis). Lines = average daily high and low (left axis). Average = each month's value averaged across every year of record (1940–2026).

Rainy days by month

About 66 rainy days a year: most in June (~11), fewest in December (~3).

Bars = average number of days with ≥ 2 mm per month. Hover for the monthly rainfall total.

Monthly wind

Average daily peak wind at 10 m, by month.

Monthly solar energy

Average daily incoming solar energy in megajoules per square metre: the record's own proxy for how sunny the month is.

Calgary month by month: what to expect

Typical conditions for each month, averaged across the full record (since 1940). Daylight is the time from sunrise to sunset. Highest and Lowest are the most extreme values in the ERA5 dataset (modelled since 1940), so they can differ from official weather-station readings.

MonthAvg highAvg lowRainRainy daysDaylightHighestLowest
January−3.5°−13.3°18 mm38.2 h14.6° (2012)−42.9° (2024)
February−0.3°−11.2°18 mm39.7 h22.2° (1992)−38.2° (1947)
March4.3°−7.3°26 mm411.5 h24.8° (2004)−37.0° (1960)
April11.5°−1.5°41 mm613.6 h28.6° (1977)−25.6° (1954)
May17.3°3.6°75 mm915.3 h33.4° (1986)−17.3° (1954)
June20.6°7.9°99 mm1116.3 h37.4° (2021)−1.9° (2000)
July24.2°10.2°69 mm815.9 h36.7° (2021)2.3° (1953)
August23.7°9.4°63 mm714.4 h38.2° (2018)−2.6° (1992)
September19.0°5.2°47 mm612.4 h33.4° (2009)−14.6° (1951)
October12.1°0.1°28 mm410.4 h27.6° (1980)−26.2° (1991)
November2.8°−6.5°22 mm38.6 h21.3° (2016)−33.4° (1959)
December−2.3°−11.4°19 mm37.7 h14.7° (2017)−39.1° (1977)

How it's changed

Year-by-year signals from 1940 to today.

Climate stripes

Annual mean shifted from 1940–1949 to 2016–2025 by +1.4°C.

Each vertical stripe is one year. Color encodes how much that year's annual mean differed from the long-term average. Average = each year's annual mean compared to the average of all years (1940–2026). cooler ← → warmer

Annual mean temperature

Long-term trend: +0.25°C per decade.

One point per year, showing the temperature averaged across the whole year. The dashed line is the least-squares long-term trend. Based on ERA5 reanalysis: modelled estimates, not station readings.

Seasonal warming

Dec–Feb is warming fastest: +0.45°C per decade.

Each faint line is one three-month period's average per year; the bold dashed line is its long-term trend. Different parts of the year often warm at different rates. Based on ERA5 reanalysis: modelled estimates, not station readings.

Hot days vs frost days

Days ≥ 30°C per year: 3.0 early in the record → 14.2 recently. Frost days: 188 → 173.

Thin lines are raw yearly counts; thick lines are the smoothed trend that removes year-to-year noise. The hot-day threshold is auto-picked per city so the line actually moves. Average = a centered 5-year rolling average to smooth weather noise.

Yearly hot & cold extremes

Hottest day since 1940 in 2018, coldest in 2024: 38.2°C / −42.9°C.

One point per year: the single hottest and coldest day recorded that year.

Annual rainfall

~526 mm/year on average. Last decade: −5% vs that average. Long-term trend: 0 mm per decade.

One bar per year of total rainfall. Dashed line is the long-term average. Average = the average annual rainfall across every year of record (1940–2026).

Day-by-day grid

Each tiny square is one calendar day across the full record, about 30,000 days per city. Use the mode switch above the chart: Anomaly colors each day by how far it ran from the historical average for that date (red = warmer, blue = cooler), Daily mean temp shows the absolute mean temperature for the day (useful to see seasons and heatwaves), and Precipitation shows daily rainfall (useful to spot wet/dry seasons and droughts). Average = the long-term average for that calendar date (1940–2026).

Frequently asked questions about Calgary

Which is the warmest month in Calgary?
On long-term average, the warmest month in Calgary is July (mean daily temperature of about 16.7°C) and the coolest is January (about −9.2°C).
How does today's temperature in Calgary compare to the historical average?
On October 19, 2026, Calgary is forecast to reach a high of 12.8°C and a low of 0.1°C. The long-term average for this date (the full record since 1940) is a high of 12.4°C and a low of 0.6°C, so today's high is about equal to that average.
How much has Calgary warmed since 1940?
Comparing the first decade of the record (1940–1949) with the most recent (2016–2025), the annual mean temperature in Calgary is about 1.4°C warmer.
How much does it rain in Calgary?
Calgary receives about 526 mm of precipitation per year on long-term average, with June typically the wettest month.
What is the average temperature in Calgary?
Over the full record (since 1940), the annual mean temperature in Calgary is about 4.0°C. The warmest month is July and the coolest is January.
What are the average temperatures in Calgary by month?
Average daily highs and lows for each month in Calgary (°C, full record since 1940): January −4°/−13°, February 0°/−11°, March 4°/−7°, April 12°/−1°, May 17°/4°, June 21°/8°, July 24°/10°, August 24°/9°, September 19°/5°, October 12°/0°, November 3°/−7°, December −2°/−11°.
What is the weather like in Calgary in summer?
June to August is summer in Calgary, and it is pleasantly warm. Afternoons run 21–24°C and nights 8–10°C; July is the warmest month. Rain eases through the season: 11 rainy days and 99 mm in June, 7 days and 63 mm in August. No season is wetter.
What is the weather like in Calgary in winter?
Winter in Calgary (December to February) is cold, with afternoons close to freezing. Expect −4 to 0°C by day and −13 to −11°C at night, with January the coldest month. Snow falls on about 3 days a month, adding up to around 18 mm of precipitation. It is the driest season of the year.
What is the weather like in Calgary in spring?
Spring in Calgary (March to May) is cool. March starts at 4°C by day and −7°C at night; by May it is 17°C and 4°C. Rain rises from 26 mm on 4 days in March to 75 mm on 9 days in May.
What is the weather like in Calgary in autumn?
September to November is autumn in Calgary, and it is cool. September still brings 19°C afternoons and 5°C nights, November only 3°C and −7°C. Rain and snow fall off from 47 mm on 6 days in September to 22 mm on 3 days in November.
How many days a year does it rain in Calgary?
On long-term average, Calgary has about 66 days a year with at least 2 mm of rain or snow. The annual total is roughly 526 mm.

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