Chatham (ON) Temperature by Month

The average annual maximum temperature in Chatham, Ontario, Canada is 15°C (59°F), with daytime highs ranging from 1°C (34°F) in January to 28°C (82°F) in July. This page covers monthly averages, day-night differences, and how Chatham compares to cities worldwide.

Depending on the time of the year, temperatures range from comfortable to very cold in Chatham. At night, minimum temperatures range from 19°C (66°F) in July to -7°C (19°F) in January.

The chart below illustrates the average maximum day and minimum night temperatures in Chatham by month:

Temperatures tend to bottom out between 4 AM and 6 AM, then climb to their daily peak around 3 PM. July, the warmest month, sees 293 hours of sunshine.

The chart below shows the average temperature throughout the year:

Chatham's average annual maximum temperature is 15°C (59°F). To put that in context, here's how it compares to a few well-known destinations:

Lisbon, Portugal averages 21°C (70°F) annually, warm summers, mild winters, and rain mainly in the cooler months.

Interlaken, Switzerland averages 8°C (46°F) a year, with cold winters and cool summers thanks to its Alpine setting.

Beijing, China averages 20°C (68°F) annually, but with big seasonal swings, very cold winters and hot summers.

Melbourne, Australia averages 20°C (68°F) annually, known for unpredictable weather, with four seasons sometimes happening in one day.

Temperature alone doesn't tell the whole story, humidity plays a big role in how warm or cold it actually feels. High humidity in summer makes the heat feel more intense, particularly once temperatures climb above 25°C. In winter, the same humidity can make cold air feel sharper than the thermometer suggests.

In the cooler months, when temperatures drop below 10°C, high humidity makes the cold feel more cutting than it would in dry conditions.

In Chatham, January is the coolest month, with average highs of 1°C (34°F) and humidity around 68%, considered high. In July, the warmest month, temperatures average 28°C (82°F) with 53% humidity, conditions that feel moderate. For a full picture, see our humidity page.

Climate temperature data is typically calculated as a 30-year average. This smooths out year-to-year variability and gives a more reliable picture of what a place is actually like, rather than what happened in any single unusual year.

The readings come from a range of sources, land-based weather stations, ocean buoys, ships, and satellites. That data is collected by weather services around the world, then pooled, quality-checked, and averaged to produce the climate records you see here.

For cities and regions with significant elevation, altitude is one of the biggest factors shaping local temperatures. As a rule of thumb, temperatures fall by around 6°C for every 1,000 metres gained, so a city at 2,000 metres will typically be around 12°C cooler than a city at sea level in the same region. Higher ground also tends to see more dramatic day-to-night temperature swings, since thinner air loses heat faster after sunset.

For more on Chatham's weather, including monthly rainfall, sunshine hours, and humidity, visit our Chatham climate page.