Plymouth (IN) Temperature by Month

Plymouth, Indiana, United States of America has an average annual maximum temperature of 15°C (59°F), ranging from 0°C (32°F) in January to 29°C (84°F) in July. Below you'll find a full monthly breakdown and a comparison with cities worldwide.

In Plymouth, temperatures can shift dramatically between warm in summer and very cold in winter. Nights follow the same pattern, with lows ranging from 16°C (61°F) in July to -9°C (16°F) in January.

The chart below illustrates the average maximum day and minimum night temperatures in Plymouth 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 309 hours of sunshine.

The chart below shows the average temperature throughout the year:

Plymouth'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.

Glasgow, Scotland averages 13°C (55°F) a year, mild but often grey, with cold winters and rarely hot summers.

Shanghai, China averages 21°C (70°F) a year, with warm summers, mild winters, and a noticeable spring and autumn.

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

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.

Whether a city sits on the coast or deep inland makes a significant difference to its climate. Coastal areas tend to have more stable temperatures year-round, large bodies of water absorb heat slowly in summer and release it gradually in winter, keeping extremes in check. Cities far from the sea don't benefit from that buffer, which is why continental climates tend to have hotter summers and colder winters than their coastal counterparts at the same latitude.

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