Climate Insights for Mission Viejo

The climate in Mission Viejo is temperate. The average annual temperature is 17°C and approximately 336mm of precipitation falls per year. January is the wettest month, receiving around 70mm of rainfall. Mission Viejo is in the Northern Hemisphere. Summer begins at the end of June and lasts through September. The summer months are: August, September, July. The coldest months are February, January, December, when temperatures can drop to 11°C.

Mission Viejo sees moderate temperature variation throughout the year, ranging from 11°C to 24°C. August is the warmest month, though highs remain moderate at 24°C with a mean of 22°C. February is the coolest month, with minimum temperatures around 11°C and an average of 14°C. Daily temperature variation is modest, with an average difference of 5°C between highs and lows. The sharpest temperature change occurs between October and November, with a 3°C shift in average temperatures.

Mission Viejo is a quite dry location, receiving approximately 336mm of precipitation annually, which averages out to around 28mm per month. The wettest month is January, averaging 70mm of rainfall. March and February also tend to see above-average precipitation. The driest month is July, with just 1mm. That's 69mm less than January, 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.

Mission Viejo is relatively calm, with an average annual wind speed of 8km/h. For context, sustained winds below 12km/h are generally light, while anything above 25km/h is considered strong. The windiest month is March, averaging 10km/h, though still comfortable for most outdoor activities. The calmest conditions occur in August, with average winds dropping to 7km/h, making it an ideal period for wind-sensitive activities. Wind conditions are fairly consistent throughout the year, varying by only 3km/h between the calmest and windiest months.

It is currently summer in Mission Viejo, which began on June 21, 2026. Mission Viejo 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 24°C, while the coldest stretch bottoms out in February near 11°C. Autumn is next, beginning on September 23, 2026 (8 days from now).

The best time to visit Mission Viejo is during April, May, June, July, August, September, October and November, when the weather is most comfortable for travellers. During these months, average temperatures hover around 19°C with modest rainfall averaging 11mm per month. By contrast, February can be quite cold with temperatures dropping to 11°C. With minimal rainfall expected, you can pack light and plan outdoor activities with confidence.

The table below shows monthly climate averages for Mission Viejo 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. 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.