Chatham, Canada Climate
The warmest month is July, with an average high of 27°C; the coldest is January, with an average low of -7°C. A normal year brings 649 mm of precipitation.
Temperature through the year
The normal daily high and low. The line marks today.
- Normal low
- Normal high
- Reanalysis extreme high
- Reanalysis extreme low
Normals for Sep 24
- Normal high
- 21°C
- Normal low
- 12°C
- Reanalysis high
- 30°Cin 2017
- Reanalysis low
- 6°Cin 2012
- Chance of a wet day
- 41%
- Daylight
- 12 h 04 min
Month by month
Averages for 1991-2020. Wet days have at least 1 mm of precipitation in the reanalysis. Each month links to its own page.
| Month | Avg high | Avg low | Warmest | Coldest | Precipitation | Wet days |
|---|---|---|---|---|---|---|
| January | -1°C | -7°C | 13°C (2008) | -23°C (1994) | 43 mm | 12.4 |
| February | 0°C | -7°C | 16°C (2017) | -28°C (2015) | 34 mm | 8.5 |
| March | 5°C | -3°C | 25°C (2012) | -20°C (1999) | 43 mm | 9.3 |
| April | 12°C | 2°C | 24°C (2010) | -8°C (2019) | 57 mm | 12.0 |
| May | 19°C | 9°C | 31°C (2018) | -2°C (2020) | 62 mm | 15.5 |
| June | 24°C | 14°C | 34°C (1994) | 4°C (2003) | 69 mm | 15.0 |
| July | 27°C | 18°C | 35°C (1995) | 9°C (2001) | 68 mm | 15.5 |
| August | 27°C | 18°C | 34°C (2001) | 9°C (1992) | 59 mm | 12.4 |
| September | 23°C | 14°C | 32°C (2002) | 2°C (1993) | 63 mm | 12.0 |
| October | 16°C | 8°C | 30°C (2007) | -1°C (1993) | 53 mm | 12.4 |
| November | 8°C | 2°C | 22°C (2015) | -9°C (2019) | 51 mm | 12.0 |
| December | 2°C | -3°C | 16°C (1998) | -18°C (2017) | 47 mm | 12.4 |
| Year | 13°C | 5°C | 649 mm | 149 |
Precipitation
Rain and melted snow together. The chance of a wet day is the share of days with at least 1 mm of precipitation in the reanalysis.
649 mm in a normal year, most in June.
Chance of a wet day
- Chance of a wet day
Humidity and comfort
NASA POWER reanalysis, 1991-2020, for the grid cell around Chatham.
The muggiest month is July, when 35 percent of days are muggy or worse, with a mean dew point of 18°C or more.
| Month | Dew point | Humidity | Dry | Comfortable | Humid | Muggy | Oppressive | Miserable |
|---|---|---|---|---|---|---|---|---|
| January | -6°C | 86% | 100% | 0% | 0% | 0% | 0% | 0% |
| February | -6°C | 84% | 100% | 0% | 0% | 0% | 0% | 0% |
| March | -3°C | 79% | 100% | 0% | 0% | 0% | 0% | 0% |
| April | 2°C | 75% | 98% | 2% | 0% | 0% | 0% | 0% |
| May | 9°C | 74% | 81% | 9% | 8% | 2% | 0% | 0% |
| June | 14°C | 73% | 37% | 28% | 20% | 15% | 1% | 0% |
| July | 17°C | 71% | 17% | 21% | 27% | 26% | 8% | 1% |
| August | 16°C | 72% | 17% | 28% | 26% | 23% | 5% | 0% |
| September | 13°C | 73% | 50% | 22% | 17% | 9% | 1% | 0% |
| October | 7°C | 76% | 86% | 10% | 3% | 1% | 0% | 0% |
| November | 2°C | 80% | 99% | 1% | 0% | 0% | 0% | 0% |
| December | -3°C | 84% | 100% | 0% | 0% | 0% | 0% | 0% |
Comfort is judged by the day's mean dew point: dry below 13°C, comfortable to 16°C, humid to 18°C, muggy to 21°C, oppressive to 24°C, miserable above.
Clouds
Average share of the sky covered, from satellite (CERES and GEWEX SRB) by way of NASA POWER, 1991-2020.
The clearest month is July, with the sky 57 percent covered on average; the cloudiest is December, at 79 percent.
Wind
The mean wind speed over the whole day, from the MERRA-2 reanalysis by way of NASA POWER. Gusts run well above it.
The windiest month is January, averaging 23.4 km/h at 10 meters (33 feet) above the ground.
Daylight and sunshine
The longest day is Jun 18, with 15 h 18 min of daylight; the shortest is Dec 19, with 9 h 04 min.
- Day length
Solar energy
Average daily sunshine reaching the ground on a flat surface, in kilowatt-hours per square meter, clouds included.
Month pages
The weather in Chatham in each month, day by day.
What this means
A normal is the average of the thirty years 1991 to 2020, the period the World Meteorological Organization and NOAA use for comparison. It is an average, not a forecast: most days depart from it, and some by a long way.
Where no station record is within reach, the extremes shown are the highest and lowest the reanalysis produced for the date in 1991-2020, not measured records.
Cloud, humidity, wind and sunshine come from a reanalysis: a weather model run over the past with every observation fed in, averaged over a grid cell about 50 km across. It is consistent everywhere on Earth; it smooths local detail such as a lake shore or a valley.
More for this place
Nearby
Sources
Cloud, humidity, wind and sunshine, and temperature and precipitation: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-24. Sun and moon: computed with the NOAA solar equations and Meeus.