Climate Insights for Arcata

The climate in Arcata is temperate. The average annual temperature is 12°C and approximately 1801mm of precipitation falls per year. October is the wettest month, receiving around 391mm of rainfall. Arcata is in the Northern Hemisphere. Summer begins at the end of June and lasts through September. The summer months are: August, July, September. The coldest months are December, January, February, when temperatures can drop to 3°C. Light snow can occur between January and December.

Arcata sees moderate temperature variation throughout the year, ranging from 3°C to 21°C. August is the warmest month, though highs remain moderate at 21°C with a mean of 16°C. December is the coolest month, with minimum temperatures around 3°C and an average of 5°C. Daily temperature variation is modest, with an average difference of 8°C between highs and lows. The sharpest temperature change occurs between November and December, with a 5°C shift in average temperatures.

Arcata is a fairly wet location, receiving approximately 1801mm of precipitation annually, which averages out to around 150mm per month. The wettest month is October, averaging 391mm of rainfall. January and March also tend to see above-average precipitation. The driest month is August, with just 2mm. That's 389mm less than October, the wettest month. Rainfall is heavily concentrated in certain months, creating a distinct wet and dry season. Visitors should plan around these patterns, as the difference between peak and low months is dramatic. Light snowfall can occur between January and December, totalling around 23cm annually. March is the snowiest month with approximately 6cm.

Arcata is relatively calm, with an average annual wind speed of 3km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is January, averaging 4km/h, though still comfortable for most outdoor activities. The calmest conditions occur in August, with average winds dropping to 2km/h, making it an ideal period for wind-sensitive activities. Wind speeds vary significantly across the year, with a 2km/h difference between the calmest and windiest months. This level of variation is worth factoring into travel plans.

It is currently summer in Arcata, which began on June 21, 2026. Arcata is in the Northern Hemisphere, where spring begins in March, summer in June, autumn in September, and winter in December. The warmest period peaks in August at around 21°C, while the coldest stretch bottoms out in December near 3°C. Autumn is next, beginning on September 23, 2026 — 52 days from now.

The best time to visit Arcata is during July and August, when the weather is most comfortable for travellers. During these months, average temperatures hover around 16°C with modest rainfall averaging 10mm per month. By contrast, December can be quite cold with temperatures dropping to 3°C. With minimal rainfall expected, you can pack light and plan outdoor activities with confidence.

The table below shows monthly climate averages for Arcata based on historical weather data. Min and max temperatures represent typical overnight lows and afternoon highs for each month, shown in degrees Celsius (°C). Precipitation is measured in millimetres (mm) and indicates the average total rainfall per month. Snow is measured in centimetres (cm) and reflects average monthly snowfall accumulation. Wind speed is the average sustained speed in kilometres per hour (km/h). All values are based on averages from over 10 years of historical weather data. The current month is highlighted for quick reference.