Calgary has 4,993.7 heating degree days and 43.7 cooling degree days in an average year. We counted 10,131 HVAC permits in 2025.
Calgary records 4,993.7 heating degree days and 43.7 cooling degree days in an average year, based on Environment and Climate Change Canada's 1991-2020 climate normals for Calgary International Airport. Heating accounts for 99.13% of the combined degree days. The report keeps climate and permit measures separate.
Sources: Calgary International Airport 1991-2020 climate normals
Calgary International Airport, base 18°C.
Calgary International Airport, base 18°C.
Calgary Reviews' calculation from City records.
| Indicator | Calgary International Airport normal | What it describes |
|---|---|---|
| Heating degree days, base 18°C | 4,993.7 per year | Accumulated daily mean temperatures below 18°C |
| Cooling degree days, base 18°C | 43.7 per year | Accumulated daily mean temperatures above 18°C |
| Heating-to-cooling degree-day ratio | 114.3:1 | The relative size of the two annual degree-day totals |
| Heating share of combined degree days | 99.13% | Heating degree days divided by combined heating and cooling degree days |
| Days with a daily minimum below -20°C | 21.6 per year | Frequency of very cold overnight conditions |
| Days with a daily maximum above 30°C | 4.8 per year | Frequency of hot daytime conditions |
| Contractor HVAC permits | 10,131 in 2025 | Calgary Reviews' calculation from the City Mechanical Permits dataset, extracted August 25, 2026 |
Sources: Calgary International Airport 1991-2020 climate normals; Mechanical Permits dataset
Heating degree days measure how far each day's mean temperature falls below 18°C. Cooling degree days measure how far each day's mean temperature rises above 18°C. Environment and Climate Change Canada sums those daily differences across the year.
Calgary International Airport averages 4,993.7 heating degree days and 43.7 cooling degree days per year. The derived ratio is 114.3 heating degree days for every cooling degree day. Heating accounts for 99.13% of the combined total.
The station also averages 61.2 days each year when the daily maximum stays at or below 0°C. The daily minimum falls below -20°C on 21.6 days and below -30°C on 3.0 days. Wind chill drops below -30°C on 14.5 days per year.
Hot conditions occur less often. Calgary International Airport averages 4.8 days per year with a daily maximum above 30°C and 8.6 days with humidex at or above 30. The 1991-2020 normal period includes recorded extremes of 36.5°C and -39.7°C.
Sources: Calgary International Airport 1991-2020 climate normals; Technical documentation for Canadian climate normals
Calgary's heating degree days are concentrated from October through April. Those seven months account for 4,248.4 heating degree days, or 85.1% of the annual normal.
Cooling degree days are concentrated in July and August. The two months account for 36.8 cooling degree days, or 84.2% of the annual normal. Calgary International Airport's July daily maximum averages 23.5°C, while its January daily minimum averages -13.5°C. The station's annual mean temperature is 4.5°C.
These monthly shares describe the timing of outdoor temperatures at the airport station. They do not show how long individual furnaces or air conditioners run inside Calgary homes.
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Sources: Calgary International Airport 1991-2020 climate normals
Calgary Reviews counted 10,131 unique contractor HVAC permits issued in 2025, based on PermitIssuedDate in the City of Calgary Mechanical Permits dataset, extracted August 25, 2026. This is Calgary Reviews' own calculation. The count was 16.4% higher than in 2024 and 153.0% higher than in 2019.
The complete 2019-2025 period contains 41,619 unique contractor HVAC permits. The Improvement WorkClassGroup accounted for 4,326 of the 10,131 permits in 2025, or 42.7%.
Permit totals measure records in the City's contractor HVAC category. The report makes no causal link between weather and changes in permit counts.
| Year | Unique contractor HVAC permits | Annual change |
|---|---|---|
| 2019 | 4,005 | Not applicable |
| 2020 | 3,624 | -9.5% |
| 2021 | 4,050 | 11.8% |
| 2022 | 4,391 | 8.4% |
| 2023 | 6,715 | 52.9% |
| 2024 | 8,703 | 29.6% |
| 2025 | 10,131 | 16.4% |
Sources: Mechanical Permits dataset
The climate indicators describe outdoor conditions at one station. They do not measure HVAC service demand or equipment performance. Household energy use and indoor comfort also fall outside the report. Heating and cooling degree days do not size HVAC equipment.
Calgary International Airport is the station used for this report. Its climate normals are a proxy for Calgary rather than a reading for every community.
Mechanical permit records repeat permit numbers across inspection rows, so this report counts each PermitNum once by PermitIssuedDate. The records cannot distinguish service calls, equipment failures, replacements or heat-pump installations. They also lack the detail needed to measure residential demand, systems installed or homes served.
Sources: Calgary International Airport 1991-2020 climate normals; Mechanical Permits dataset
The two aggregate tables published in this report, normalized into one CSV. The file contains no row-level permit records.
Provenance: Calgary Reviews transcribed only the aggregate values visible in this report's two tables. Climate values come from ECCC normals. Permit counts are Calgary Reviews' deduplicated calculations from the City dataset extracted August 25, 2026.
Sources: Calgary International Airport 1991-2020 climate normals; Mechanical Permits dataset
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