Arcata (CA) Temperature by Month

Arcata, California, United States of America has an average annual maximum temperature of 16°C (61°F), with moderate seasonal shifts ranging from 12°C (54°F) in December to 20°C (68°F) in September. Below you'll find a full monthly breakdown and a comparison with cities worldwide.

Seasonal changes in Arcata bring a little variety without extreme temperature swings. Nighttime lows range from 10°C (50°F) in September to 4°C (39°F) in December.

The chart below illustrates the average maximum day and minimum night temperatures in Arcata 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:

Arcata's average annual maximum temperature is 16°C (61°F). To put that in context, here's how it compares to a few well-known destinations:

Rome, Italy averages 20°C (68°F) annually, with reliably warm summers and comfortable winters.

Reykjavík, Iceland averages 9°C (48°F) a year, mild summers by Icelandic standards, but cold winters and frequent wind.

Boston, USA averages 16°C (61°F) annually, with four distinct seasons and cold winters that rival northern Europe.

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