Dewey Beach (DE) Temperature by Month

The average annual maximum temperature in Dewey Beach, Delaware, United States of America is 19°C (66°F), with daytime highs ranging from 7°C (45°F) in January to 31°C (88°F) in July. This page covers monthly averages, day-night differences, and how Dewey Beach compares to cities worldwide.

Depending on the time of the year, temperatures range from very warm to cold in Dewey Beach. At night, minimum temperatures range from 22°C (72°F) in July to -2°C (28°F) in January.

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

From around 4 AM to 6 AM temperatures are at their lowest; by 3 PM they've climbed to their daily peak.

The chart below shows the average temperature throughout the year:

Dewey Beach's average annual maximum temperature is 19°C (66°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.

Buenos Aires, Argentina averages 23°C (73°F) a year, with hot summers and mild winters, and seasons reversed compared to Europe.

Adelaide, Australia averages 21°C (70°F) a year, with warm summers, mild winters, and relatively low rainfall year-round.

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.

Global average temperatures have risen by around 1.2°C since the pre-industrial era, and the effects are visible across many regions. Winters are milder on average, with fewer frost days and less snow in many parts of the world. Heatwaves are more frequent and more intense, and Europe's summers of 2018, 2019, and 2020 all set records.

Summers are also getting drier in some areas, while winter rainfall has increased in others. This contributies to higher river levels and more flooding. In many countries, spring arrives earlier and autumn lasts longer. It has knock-on effects for wildlife, agriculture, and local ecosystems.

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