Guelph (ON) Temperature by Month

Guelph, Ontario, Canada has an average annual maximum temperature of 13°C (55°F), ranging from -1°C (30°F) in January to 27°C (81°F) in July. Below you'll find a full monthly breakdown and a comparison with cities worldwide.

The climate in Guelph is dynamic, ranging widely from very cold in winter to comfortable in summer. Nights are significantly colder, with lows dropping from 15°C (59°F) in July to -10°C (14°F) in January.

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

The coldest point of the day usually falls between 4 AM and 6 AM, with temperatures peaking around 3 PM. July, the city's warmest month, gets 305 hours of sunshine.

The chart below shows the average temperature throughout the year:

Guelph's average annual maximum temperature is 13°C (55°F). To put that in context, here's how it compares to a few well-known destinations:

Athens, Greece sits at 23°C (73°F) on average, with hot dry summers and mild winters characteristic of the Mediterranean.

Toronto, Canada averages 13°C (55°F) annually, with cold snowy winters balanced by genuinely warm summers.

New York City, USA averages 17°C (63°F) a year, with hot humid summers and cold winters that bring regular snowfall.

Brisbane, Australia averages 26°C (79°F) a year, with warm winters and hot, humid summers.

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 Guelph's weather, including monthly rainfall, sunshine hours, and humidity, visit our Guelph climate page.