Hamilton (MT) Temperature by Month
The average annual maximum temperature in Hamilton, Montana, United States of America is 15°C (59°F), with daytime highs ranging from 2°C (36°F) in December to 31°C (88°F) in July. This page covers monthly averages, day-night differences, and how Hamilton compares to cities worldwide.
Hamilton Monthly Temperatures
The climate in Hamilton is dynamic, ranging widely from very cold in winter to very warm in summer. Nights are significantly colder, with lows dropping from 10°C (50°F) in July to -8°C (18°F) in December.
The chart below illustrates the average maximum day and minimum night temperatures in Hamilton by month:
Temperatures tend to bottom out between 4 AM and 6 AM, then climb to their daily peak around 3 PM.
The chart below shows the average temperature throughout the year:
Temperature: Hamilton vs the United States of America
The map below shows the annual temperature across the United States of America. You can also select individual months if you want to compare a specific time of year.
very warm
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moderate
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Hamilton vs World: Temperature Compared
Hamilton'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.
Toronto, Canada averages 13°C (55°F) annually, with cold snowy winters balanced by genuinely warm summers.
Boston, USA averages 16°C (61°F) annually, with four distinct seasons and cold winters that rival northern Europe.
Perth, Australia averages 25°C (77°F) annually, with a classic Mediterranean climate — hot dry summers and mild wet winters.
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.
Seasonal temperature shifts influence more than just how warm it feels — they also drive changes in rainfall, cloud cover, and wind patterns throughout the year.
Warmer air holds more moisture, which tends to mean heavier or more frequent rain during the warmer months. When temperatures drop in winter, any precipitation that does fall is more likely to come as snow or sleet, though in Hamilton this rarely lasts long on the ground.
For more on Hamilton's weather — including monthly rainfall, sunshine hours, and humidity — visit our Hamilton climate page.
