South Yarmouth (MA) Temperature by Month

The average annual maximum temperature in South Yarmouth, Massachusetts, United States of America is 15°C (59°F), with daytime highs ranging from 4°C (39°F) in February to 26°C (79°F) in July. This page covers monthly averages, day-night differences, and how South Yarmouth compares to cities worldwide.

In South Yarmouth, temperatures can shift dramatically between warm in summer and cold in winter. Nights follow the same pattern, with lows ranging from 19°C (66°F) in July to -4°C (25°F) in February.

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

Daily lows are most common between 4 AM and 6 AM. By 3 PM temperatures reach their daily high, driven by peak solar heating. July, the warmest month of the year, receives 301 hours of sunshine.

The chart below shows the average temperature throughout the year:

South Yarmouth'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:

Barcelona, Spain has an annual average of around 21°C (70°F), with warm summers and mild, fairly short winters.

On the cooler end, Oslo, Norway averages just 10°C (50°F) annually, with pleasant summers but long, cold winters.

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.

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