Nepean, Ontario Weather by Month and Climate Averages
December is the warmest month (average high -3°C) and January the coldest (average low -13°C).
Nepean climate at a glance
Does it snow in Nepean?
The snowiest winter on record is 2022–23, with 329 cm.
The most recent measurable snow at the station fell on April 5, 2024.
Nepean weather by month
Nepean weather in January
In January, Nepean averages a high of -5°C and a low of -13°C. The sun is out about 27% of daylight hours. The January record high is 12°C (2018) and the record low is -30°C (2018).
Nepean weather in December
In December, Nepean averages a high of -3°C and a low of -11°C. The sun is out about 20% of daylight hours. The December record high is 18°C (2012) and the record low is -28°C (2016).
Sunshine, humidity and wind in Nepean
July is the sunniest month in Nepean, with sunshine about 44% of daylight hours. December is the cloudiest, at 20%. Over the year the sun shines about 36% of daylight hours. Nepean is cloudier than 55% of Canada.
Humidity peaks in December at 78% and is lowest in May at 57%.
Nepean has about 8 days a year above 32°C. Nepean is hotter than 84% of Canada.
Nepean weather records
The hottest temperature on record at the Nepean station is 37°C, on July 10, 2020. The coldest is -33°C, on February 4, 2023.
The wettest day on record brought 79 mm of rain, on July 24, 2017.
Monthly climate
| Month | Precip | Rain days | Humidity | Sunshine | Record high | Record low |
|---|---|---|---|---|---|---|
| January | — | — | 77% | 27% | 12° | -30° |
| February | — | — | 71% | 33% | 16° | -33° |
| March | — | — | 64% | 32% | 27° | -23° |
| April | — | — | 58% | 36% | 30° | -12° |
| May | — | — | 57% | 43% | 35° | -4° |
| June | — | — | 66% | 39% | 35° | 1° |
| July | — | — | 71% | 44% | 37° | 8° |
| August | — | — | 76% | 41% | 36° | 6° |
| September | — | — | 76% | 44% | 33° | -1° |
| October | — | — | 76% | 36% | 31° | -8° |
| November | — | — | 74% | 34% | 23° | -21° |
| December | 67 mm | 15 | 78% | 20% | 18° | -28° |
From ERA5 reanalysis. Sunshine is estimated from cloud cover.
Nepean climate questions
What is the hottest month in Nepean?
December is the warmest month in Nepean, with an average high of -3°C.
What is the coldest month in Nepean?
January is the coldest month in Nepean, with an average low of -13°C.
What is the record high temperature in Nepean?
The record high at the Nepean station is 37°C, set on July 10, 2020. The record low is -33°C, on February 4, 2023.
What is the sunniest month in Nepean?
July is the sunniest month in Nepean, with sunshine about 44% of daylight hours. December is the cloudiest.
Source: NOAA GHCN-Daily station OTTAWA INT'L (5 km away).
Climate for places near Nepean, Ontario
Normals from NOAA GHCN-Daily station OTTAWA INT'L.