Québec design temperatures: table by city

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What is a design temperature?

A heating system is not designed for the most extreme cold ever recorded, but for severe cold that is only rarely exceeded. Appendix C of the National Building Code of Canada (NBC) 2020 defines the January design temperature as the lowest temperature at or below which only a small percentage of January hours occur. The 2.5% value corresponds on average to about 19 colder hours per January; the 1% value, to about 8 hours.

According to the Code, the 2.5% value is the one ordinarily used to design heating systems; the 1% value is used where control of the indoor temperature is more critical. The values were updated using hourly observations from 480 stations over a 25-year period ending in 2006. Because most stations are at airports, the Code notes that the core of large cities may be 1 to 2 °C milder.

Why not the average temperature?

A monthly average hides cold snaps. A house’s heat loss grows with the indoor–outdoor temperature difference, so the required capacity peaks during the coldest hours. Degree-days, on the other hand, measure energy used over the whole season; they are used to estimate an annual bill (as in our cost analysis), not peak capacity.

How to use it to choose a heat pump (NRCan approach)

Calculate the heating load at the design temperature for your location (a load calculation done by a professional, for example using the CSA F280 standard). The BTU/h per sq ft range from our estimator is only a ballpark figure.
Choose an approach. The Air-Source Heat Pump Sizing and Selection Guide from Natural Resources Canada (NRCan) offers, among others: option 4C, where the heat pump’s capacity is close to (preferably above) the house’s load at −8.3 °C (17 °F), with backup heat in extreme cold; and option 4D, where its capacity at the design temperature is close to the design load (above it to go without backup). For option 4D, NRCan states that a cold-climate heat pump is required in most Canadian climate zones.
Estimate the load at −8.3 °C. Equation 4 of the NRCan guide scales the design load to −8.3 °C by assuming the load is proportional to the difference from 15.6 °C (60 °F). Site calculation with this equation: in Montréal (−23 °C), the load at −8.3 °C is about 62% of the design load; in Sept-Îles (−29 °C), about 54%.
Check the manufacturer’s data. NRCan strongly recommends using the manufacturer’s extended performance data (actual capacity at low temperatures). Also check the unit’s minimum operating temperature.
Plan for backup heat. Below the balance point (the temperature at which the heat pump’s capacity equals the house’s heat loss), backup heat (baseboards, furnace) covers the gap.

The LogisVert rebate is based on capacity at −8 °C: see the 2026–2027 rebates.

Table: Québec design temperatures (NBC 2020)

124 Québec locations, as listed in Table C-2. In brackets: the current municipality, where the table name is a former name or a sector. Click a column header to sort.

Search for a location

January design temperatures, degree-days below 18 °C and elevation — NBC 2020, Division B, Appendix C, Table C-2 (Quebec section)

Acton Vale	−24	−27	4620	95
Alma	−31	−33	5800	110
Amos	−34	−36	6160	295
Ancienne-Lorette	−25	−28	5130	35
Asbestos (Val-des-Sources)	−26	−28	4800	245
Aylmer (Gatineau)	−25	−28	4520	90
Baie-Comeau	−27	−29	6020	60
Baie-Saint-Paul	−27	−29	5280	20
Beaconsfield	−24	−26	4440	25
Beauport	−26	−29	5100	45
Bedford	−24	−26	4420	55
Beloeil	−24	−26	4500	25
Brome	−25	−27	4730	210
Brossard	−24	−26	4420	15
Buckingham	−26	−28	4880	130
Campbell's Bay	−28	−30	4900	115
Chambly	−24	−26	4450	20
Coaticook	−25	−27	4750	295
Contrecoeur	−25	−27	4500	10
Cowansville	−25	−27	4540	120
Deux-Montagnes	−25	−27	4440	25
Dolbeau (Dolbeau-Mistassini)	−32	−34	6250	120
Dorval	−24	−26	4400	25
Drummondville	−26	−28	4700	85
Farnham	−24	−26	4500	60
Fort-Coulonge	−28	−30	4950	110
Gagnon	−34	−36	7600	545
Gaspé	−25	−26	5500	55
Gatineau	−25	−28	4600	95
Gracefield	−28	−31	5080	175
Granby	−25	−27	4500	120
Harrington Harbour	−27	−29	6150	30
Havre-Saint-Pierre	−27	−29	6100	5
Hemmingford	−24	−26	4380	75
Hull (Gatineau)	−25	−28	4550	65
Iberville	−24	−26	4450	35
Inukjuak	−36	−38	9150	5
Joliette	−26	−28	4720	45
Kuujjuaq	−37	−39	8550	25
Kuujjuarapik	−36	−38	7990	20
La Malbaie	−26	−28	5400	25
La Pocatière	−24	−26	5160	55
La Tuque	−30	−32	5500	165
Lac-Mégantic	−27	−29	5180	420
Lachute	−26	−28	4640	65
Laval	−24	−26	4500	35
Lennoxville	−28	−30	4700	155
Léry	−24	−26	4420	30
Lévis	−25	−28	5050	50
Loretteville	−26	−29	5200	100
Louiseville	−25	−28	4900	15
Magog	−26	−28	4730	215
Malartic	−33	−36	6200	325
Maniwaki	−30	−32	5280	180
Masson	−26	−28	4610	50
Matane	−24	−26	5510	5
Mont-Joli	−24	−26	5370	90
Mont-Laurier	−29	−32	5320	225
Montmagny	−25	−28	5090	10
Montréal (City Hall)	−23	−26	4200	20
Montréal-Est	−23	−26	4470	25
Montréal-Nord	−24	−26	4470	20
Nicolet (Gentilly)	−25	−28	4900	15
Nitchequon	−39	−41	8100	545
Noranda (Rouyn-Noranda)	−33	−36	6050	305
Outremont	−23	−26	4300	105
Percé	−21	−24	5400	5
Pierrefonds	−24	−26	4430	25
Pincourt	−24	−26	4480	25
Plessisville	−26	−28	5100	145
Port-Cartier	−28	−30	6060	20
Puvirnituq	−36	−38	9200	5
Québec	−25	−28	5080	120
Richmond	−25	−27	4700	150
Rimouski	−25	−27	5300	30
Rivière-du-Loup	−25	−27	5380	55
Roberval	−31	−33	5750	100
Rock Island	−25	−27	4850	160
Rosemère	−24	−26	4550	25
Rouyn (Rouyn-Noranda)	−33	−36	6050	300
Saguenay	−30	−32	5700	10
Saguenay (Bagotville)	−31	−33	5700	5
Saguenay (Jonquière)	−30	−32	5650	135
Saguenay (Kénogami)	−30	−32	5650	140
Saint-Eustache	−25	−27	4500	35
Saint-Félicien	−32	−34	5850	105
Saint-Georges-de-Cacouna	−25	−27	5400	35
Saint-Hubert (Longueuil)	−24	−26	4490	25
Saint-Hubert-de-Rivière-du-Loup	−26	−28	5520	310
Saint-Hyacinthe	−24	−27	4500	35
Saint-Jean-sur-Richelieu	−24	−26	4450	35
Saint-Jérôme	−26	−28	4820	95
Saint-Jovite (Mont-Tremblant)	−29	−31	5250	230
Saint-Lambert	−23	−26	4400	15
Saint-Laurent	−23	−26	4270	45
Saint-Lazare / Hudson	−24	−26	4520	60
Saint-Nicolas	−25	−28	4990	65
Sainte-Agathe-des-Monts	−28	−30	5390	360
Sainte-Anne-de-Bellevue	−24	−26	4460	35
Sainte-Foy	−25	−28	5100	115
Salaberry-de-Valleyfield	−23	−25	4400	50
Schefferville	−37	−39	8550	550
Senneterre	−34	−36	6180	310
Sept-Îles	−29	−31	6200	5
Shawinigan	−26	−29	5050	60
Shawville	−27	−30	4880	170
Sherbrooke	−28	−30	4700	185
Sillery	−25	−28	5070	10
Sorel (Sorel-Tracy)	−25	−27	4550	10
Sutton	−25	−27	4600	185
Tadoussac	−26	−28	5450	65
Témiscaming	−30	−32	5020	240
Terrebonne	−25	−27	4500	20
Thetford Mines	−26	−28	5120	330
Thurso	−26	−28	4820	50
Trois-Rivières	−25	−28	4900	25
Val-d'Or	−33	−36	6180	310
Varennes	−24	−26	4500	15
Verchères	−24	−26	4450	15
Verdun	−23	−26	4200	20
Victoriaville	−26	−28	4900	125
Ville-Marie	−31	−34	5550	200
Wakefield	−27	−30	4820	120
Waterloo	−25	−27	4650	205

Several large cities are not in the table (for example Repentigny, Mirabel, Blainville, Châteauguay or Saint-Georges in Beauce). Note: Saint-Georges-de-Cacouna is in Bas-Saint-Laurent. The NBC states that interpolation may not be valid and that Environment and Climate Change Canada provides recommended values on request (scg-ecs@ec.gc.ca). This site publishes no estimated values.

Edition and regulatory context

Data from the National Building Code of Canada 2020 (National Research Council Canada), second printing including the revisions and errata of March 31, 2025, Division B, Appendix C, Table C-2. Appendix C is explanatory (not part of the requirements). In Québec, Chapter I (Building) of the Construction Code adopts the NBC with modifications: check with the RBQ or your municipality which edition and values apply to your project. This guide is not a calculation compliant with CSA F280 or any other standard method.

Frequently asked questions

What is the design temperature in Montréal?

According to NBC 2020 Table C-2: −23 °C at 2.5% for Montréal (City Hall) and −24 °C for Dorval, near the airport. The 1% value is −26 °C for both.

My municipality is not in the table. What should I do?

The NBC notes that interpolating between locations may not be valid. Environment and Climate Change Canada provides recommended values for unlisted locations on request; local authorities may also set their own values. This site does not estimate any missing value.

Must my heat pump heat on its own at the design temperature?

Not necessarily. The NRCan guide offers two heating-focused approaches: choose capacity at −8.3 °C (17 °F) with backup heat in extreme cold, or target the full load at the design temperature, often with a cold-climate model.

Why do the degree-days differ from the estimator’s?

The estimator uses ECCC 1981–2010 climate normals for a specific station; Table C-2 gives the Code values for the location. Periods and methods differ, hence small gaps.

Sources

NRC, National Building Code of Canada 2020, Division B, Appendix C (Table C-2). Verified October 16, 2026.
NRCan, Air-Source Heat Pump Sizing and Selection Guide, version 1.0 (2020-12-21), Step 4, options 4C and 4D. Verified October 16, 2026.

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