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Greater Sudbury weather by month: averages, rainfall & climate trends

Greater Sudbury swings through a wide annual range, with 31.0°C between the monthly means of its warmest and coldest months. Rainfall is spread quite evenly across the year. Greater Sudbury weather by month: average temperatures, rainfall, records and how the climate has changed since 1940.

Today vs average

−0.7°Chigh near average

11° / −1°Today
11° / 4°Average
see today in detail →

How it's changed

+1.3°Caverage temperature, 2016–2025 vs 1940–1949average temperature vs 1940–49167frost days a year now (2016–2025) · 170 in the 1940sfrost days a year · 170 in the 1940s7days above 30°C a year now (2016–2025) · 2 in the 1940sdays above 30°C · 2 in the 1940s+1.3°C vs the 1940s · see how it's changed →
Weather by montha typical year, averaged over the full recordJanuary, rain 56 mmhigh −7°low −17°February, rain 46 mmhigh −5°low −15°March, rain 60 mmhigh 1°low −9°April, rain 71 mmhigh 9°low −1°May, rain 75 mmhigh 17°low 6°June, rain 83 mmhigh 22°low 11°July, rain 89 mmhigh 25°low 14°August, rain 88 mmhigh 23°low 13°September, rain 91 mmhigh 18°low 9°October, rain 84 mmhigh 11°low 3°November, rain 76 mmhigh 3°low −4°December, rain 63 mmhigh −4°low −13°wettest month September, 91 mm · 881 mm a yearsee month by month →

Right now

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

Right now

7.1°

5°feels like
84%humidity
5°dew point
4 km/hfrom S
UV index0.0
sunrise07:41sunset18:37day length10h 56m
TodayClear11°−1°
FriOvercast6°0°
SatClear9°−1°
SunClear14°2°
MonOvercast16°8°
TueClear14°5°
WedClear10°0°

On this date: October 15

Today (forecast)
11° / −1°
Average for October 15
11° / 4°

High near average · −0.7°C

  • Record high: 23.8° · 1968
  • Record low: −6.2° · 1978
  • One year ago: 12° / 3°

Every October 15 in history, coldest to hottest

▲ Daily highs▼ Daily lows

Dots show daily highs (top) and lows (bottom) for each October 15 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 Greater Sudbury is sampled from the ECMWF ERA5 reanalysis at 46.49°N, 80.99°W, with daily records since 1940.

Coordinates
46.49°N, 80.99°W
Time zone
America/Toronto
Period
1940–2026
Data source
ERA5 (ECMWF)

Last 30 days

17 of the last 31 days were warmer than the historical average for that date. Average difference: +0.8°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

The year peaks in July, at around 24.7°C by mid-afternoon, with nights around 13.8°C. The coolest month is January, when afternoons reach about −7.0°C and overnight lows sit around −16.6°C. Around 165 days a year dip below freezing.

In total, Greater Sudbury averages about 881 mm of precipitation a year; September is usually the wettest month (91 mm) and February the driest (46 mm).

Comparing the record's first decade with its most recent one, Greater Sudbury now averages 1.3°C warmer than it did in the 1940s. You can follow the shift year by year in the charts below.

Climate graph (climograph)

July is the warmest month, January the coolest: a yearly swing of 31°C. Wettest month: September (~91 mm). Whole year averages ~881 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 101 rainy days a year: most in September (~9), fewest in February (~6).

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.

Greater Sudbury 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. Record high/low are the most extreme values in the ERA5 dataset (modelled since 1940), so they can differ from official weather-station readings.

MonthAvg highAvg lowRainRainy daysDaylightRecord highRecord low
January−7.0°−16.6°56 mm88.8 h11.7° (1950)−40.5° (1981)
February−5.0°−15.1°46 mm610.1 h9.8° (2017)−36.2° (1967)
March1.0°−9.2°60 mm711.6 h24.8° (2012)−35.9° (2003)
April9.3°−1.3°71 mm813.3 h30.9° (1990)−24.2° (2018)
May17.5°5.5°75 mm914.8 h33.9° (2010)−8.0° (1943)
June22.4°11.0°83 mm915.6 h35.9° (1995)0.0° (1972)
July24.7°13.8°89 mm915.3 h37.9° (1975)4.7° (1992)
August23.2°13.0°88 mm914.0 h35.1° (2001)1.7° (1965)
September18.3°8.7°91 mm912.3 h33.5° (1953)−3.5° (2000)
October11.3°3.0°84 mm910.6 h28.1° (2025)−10.4° (2020)
November3.1°−3.8°76 mm99.1 h20.3° (2020)−28.0° (1989)
December−4.0°−12.7°63 mm98.4 h14.2° (1982)−37.9° (1980)

How it's changed

Year-by-year signals from 1940 to today.

Climate stripes

Annual mean shifted from 1940–1949 to 2016–2025 by +1.3°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: +0.19°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

Mar–May is warming fastest: +0.30°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: 2.0 early in the record → 7.4 recently. Frost days: 170 → 167.

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

All-time high in 1975, all-time low in 1981: 37.9°C / −40.5°C.

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

Annual rainfall

~881 mm/year on average. Last decade: +7% vs that average. Long-term trend: +12 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 Greater Sudbury

Which is the warmest month in Greater Sudbury?
On long-term average, the warmest month in Greater Sudbury is July (mean daily temperature of about 19.0°C) and the coolest is January (about −12.0°C).
How does today's temperature in Greater Sudbury compare to the historical average?
On October 15, 2026, Greater Sudbury is forecast to reach a high of 10.8°C and a low of −0.9°C. The long-term average for this date (the full record since 1940) is a high of 11.5°C and a low of 3.6°C, so today's high is 0.7°C cooler than that average.
How much has Greater Sudbury warmed since 1940?
Comparing the first decade of the record (1940–1949) with the most recent (2016–2025), the annual mean temperature in Greater Sudbury is about 1.3°C warmer.
How much does it rain in Greater Sudbury?
Greater Sudbury receives about 881 mm of precipitation per year on long-term average, with September typically the wettest month.
What is the average temperature in Greater Sudbury?
Over the full record (since 1940), the annual mean temperature in Greater Sudbury is about 4.4°C. The warmest month is July and the coolest is January.
What are the average temperatures in Greater Sudbury by month?
Average daily highs and lows for each month in Greater Sudbury (°C, full record since 1940): January −7°/−17°, February −5°/−15°, March 1°/−9°, April 9°/−1°, May 17°/6°, June 22°/11°, July 25°/14°, August 23°/13°, September 18°/9°, October 11°/3°, November 3°/−4°, December −4°/−13°.
What is the weather like in Greater Sudbury in summer?
June to August is summer in Greater Sudbury, and it is pleasantly warm. Afternoons run 22–25°C and nights 11–14°C; July is the warmest month. Rain is steady at around 87 mm a month, spread over roughly 9 days.
What is the weather like in Greater Sudbury in winter?
In winter, December through February, Greater Sudbury is freezing. Expect −7 to −4°C by day and −17 to −13°C at night, with January the coldest month. Snow is steady at around 55 mm of precipitation a month, spread over roughly 8 days. It is the driest season of the year.
What is the weather like in Greater Sudbury in spring?
Spring in Greater Sudbury (March to May) is on the cool side. March is still 1°C in the afternoon and −9°C at night, May already 17°C and 6°C. Rain and snow are steady at around 68 mm a month, spread over roughly 8 days.
What is the weather like in Greater Sudbury in autumn?
In autumn, September through November, Greater Sudbury is on the cool side. September is still 18°C by day and 9°C at night; by November it is down to 3°C and −4°C. Rain and snow fall on about 9 days a month, adding up to around 84 mm.
How many days a year does it rain in Greater Sudbury?
On long-term average, Greater Sudbury has about 101 days a year with at least 2 mm of rain or snow. The annual total is roughly 881 mm.

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