Photo: Royalbroil · CC BY-SA 4.0Hardly any Canadian towns see more snow than Mattawa, with about 312 cm a year
The coldest hours of a January night bottom out at −16.0°C on average. Some 42°C separates winter nights from summer afternoons. By January nights alone, it runs colder than 75% of Canadian towns. An umbrella or a shovel earns its place on about 133 days a year with 1 mm or more.
Mattawa has no ECCC normals station nearby: the figures come from Barrage Témiscamingue, 53 km north-west, so read them as the wider area’s climate.
A year in Mattawa at a glance
Each month’s typical high and low, in °C.
What stands out about Mattawa’s climate
Compared with Canadian towns, with its place among towns of 2,500+ in Ontario beside it.
What a year in Mattawa feels like
Seasons and months as ECCC’s 1991–2020 normals give them: a typical day’s high and low.
About 169 frosts and 105 warm days a year
Frost comes from October to May; in January almost every night freezes. Some 24 nights a year drop under −20°C.
Frost days by month
Average days at 0°C or below
Days above 20°C by month
Average days
About 1,020 mm of rain and snow a year
September is the wettest month and February the driest.
Rain and snow by month
Millimetres
Rain alone by month
Millimetres
ECCC’s Barrage Témiscamingue normals leave out precipitation and snow; both come from North Bay here, 55 km away.
About 312 cm of snow a year
From October to May snow is likely; December is the peak, at about 71 cm.
Snowfall by month
Centimetres
Heating a home in Mattawa
90% of a year’s heating need falls between October and April. Months averaging under 10°C: October to April.
Each day the mean sits under 18°C adds its shortfall; a year’s total is its heating degree days. By this count, homes here need more heating than 61% of Canadian towns.
Living with Mattawa’s climate
What the normals mean for a garden, a day outside and the depth of winter.
Plan time outside for Jun, Jul, Aug and Sep: highs of 17–27°C and nights no colder than 8°C.
Parks & trails →A wind chill below −20 is part of about 50 days a year here.
The humidex tops 30 on about 32 days a year: muggy days to plan around.
The normals describe a typical year, not its worst days; the hazards page covers Mattawa’s.
Flood & hazards →ECCC’s normals location: Barrage Témiscamingue
The page’s figures are ECCC’s 1991–2020 normals for Barrage Témiscamingue, one of its 450 normals locations.
| Distance from the town | 53 km north-west |
| Station altitude | 181 m |
| Completeness | meets the WMO “3 and 5” rule |
| WMO standard normals | No |
| Precipitation from | North Bay, 55 km |
| Coldest reading, 1991–2020 | −35.0°C |
| Hottest reading, 1991–2020 | 35.6°C |
| Average wind | 9.0 km/h on average, most often from the south |
| Next-nearest location | North Bay, 55 km |
How Mattawa compares
Against the 2,611 Canadian towns and neighbourhoods of 2,500 or more, each read from its own normals location; the dots are the other locations those towns use in Ontario.
Nearby towns’ climate
The nearest places on a normals location of their own: those that share Mattawa’s would only repeat its figures. The one place listed is 34 km from Mattawa, the nearest with figures.
| Town | July high | January low | Rain & snow |
|---|---|---|---|
| Mattawa Barrage Témiscamingue | 25.5°C | −16.0°C | 1,020 mm |
| Bonfield 34 km · North Bay | 24.3°C 1.2°C cooler | −17.3°C 1.3°C colder | 1,020 mm |
Mattawa weather by month
Month by month, 1991–2020: the usual high, low and mean, the rain and snow, and the snowfall.
| Month | High | Low | Mean | Rain & snow | Snow |
|---|---|---|---|---|---|
| January | −6.3°C | −16.0°C | −11.2°C | 70 mm | 70 cm |
| February | −4.3°C | −15.2°C | −9.8°C | 54 mm | 63 cm |
| March | 1.9°C | −9.8°C | −4.0°C | 60 mm | 39 cm |
| April | 9.3°C | −2.1°C | 3.7°C | 72 mm | 18 cm |
| May | 17.8°C | 3.9°C | 10.9°C | 89 mm | 4 cm |
| June | 22.9°C | 10.1°C | 16.5°C | 91 mm | under 1 cm |
| July | 25.5°C | 13.6°C | 19.6°C | 98 mm | 0 cm |
| August | 24.1°C | 13.2°C | 18.7°C | 93 mm | 0 cm |
| September | 19.4°C | 9.0°C | 14.2°C | 114 mm | under 1 cm |
| October | 11.6°C | 3.4°C | 7.5°C | 109 mm | 9 cm |
| November | 4.0°C | −3.0°C | 0.5°C | 97 mm | 38 cm |
| December | −2.6°C | −10.2°C | −6.5°C | 73 mm | 71 cm |
| Year | 10.3°C | −0.3°C | 5.0°C | 1,020 mm | 312 cm |
A March here can run from −30.0°C to 27.3°C
Bars run from each month’s record low to its record high over 1991–2020; January is the month whose average wanders most from year to year (±3.4°C around −11.2°C), June the one that wanders least (±1.1°C).
Where Mattawa’s numbers come from
Averages over 30 years, not a forecast.
- Normals: ECCC’s normals for Barrage Témiscamingue, 1991–2020, chosen as the nearest location with a full temperature record.
- Other locations: precipitation and snowfall come from the nearest location that publishes all twelve months of them, as named above.
- Comparisons: the 2,500-plus towns and neighbourhoods of Canada, each read from its closest normals location; whole cities and reserves aren’t counted.
- Not on this page: a sunshine figure (ECCC published none for 1991–2020) and any lapse-rate correction for height, as the town has no elevation here.
Canadian Climate Normals 1991–2020 · ECCC Data Services End-use Licence. Data Source: Environment and Climate Change Canada
Questions about Mattawa’s climate
How warm does Mattawa get in summer?
July is the warmest month, with average highs of 25.5°C.
How cold does Mattawa get in winter?
Midwinter means January, when a typical night reaches −16.0°C.
How much rain and snow does Mattawa get?
A normal year brings 1,020 mm, snow included as water: September is wettest at 114 mm, February driest at 54 mm.
Are these figures for Mattawa itself?
No: they come from Barrage Témiscamingue, the nearest ECCC normals location, and far enough away to describe the wider area more than Mattawa.
Data Source: Environment and Climate Change Canada · ECCC Data Services End-use Licence Today’s forecast for Mattawa →
Adapted from Statistics Canada (Census of Population 2021, population estimates 2025, 2021 census boundaries) under the Statistics Canada Open Licence; this does not constitute an endorsement by Statistics Canada. Neighbourhood names in some cities © OpenStreetMap contributors (ODbL).