San Dimas (CA) Weather & Climate: Best Time to Visit
Average temperatures, rainfall, sunshine and the best time to visit San Dimas.
Climate overview of San Dimas
San Dimas, California, United States of America, experiences significant temperature variation throughout the year. Summers bring daytime highs of 33°C (91°F) in August, while winters cool to 19°C (66°F) in December.
Rainfall is modest, totalling around 344 mm (14 in) annually. The city experiences a distinct dry season from April to November, with very warm summers and pleasant winters. December tends to be the wettest month. The most sunshine falls in July, with an average of 12.3 hours of daily sunshine.
San Dimas Weather by Month
Pick a month to see the average temperature, rainfall and sunshine in San Dimas - and find the best time to visit.
Monthly Temperature in San Dimas
Depending on the time of the year, temperatures range from very warm to pleasant in San Dimas. Average maximum daytime temperatures range from a very warm 33°C (91°F) in August, the warmest time of the year, to a pleasant 19°C (66°F) during cooler months like December.
At night, you can expect temperatures ranging from 17°C (63°F) in August to around 6°C (43°F) during December.
Check out our detailed temperature page for more information.
Temperature ranges by month
Rainfall in San Dimas
With annual rainfall averaging 344 mm (14 in), San Dimas maintains relatively low precipitation levels throughout the seasons. Significant seasonal changes in precipitation occur throughout the year. In the wettest month, December it receives moderate rainfall, averaging 93 mm (3.7 in) of precipitation, recorded across 9 rainy days. In contrast, the driest month June brings less rainfall, with 0.2 mm (0.01 in) over 0 rainy days. For more details, please visit our San Dimas Precipitation page.
The mean monthly precipitation over the year, including rain, hail, and snow
The average number of days each month with precipitation
Sunshine Hours in San Dimas
Seasonal changes in sunshine hours are quite dramatic in San Dimas. While July receives considerable daily sunshine with up to 12.3 hours, January marks the darkest time of the year, where sunshine is scarce with only 6.6 hours of sunlight per day.
Visit our detailed sunshine hours page for more information.
Monthly hours of sunshine
Daily hours of sunshine
Best Time to Visit San Dimas
Monthly ratings reflect general weather comfort, based on daytime temperature and rainfall. Swimming and winter conditions are highlighted separately where relevant.
- Best overall: January, February, March, April, May, October and November
- Warmest weather: July, August and September
- Most sunshine: July and August
- Fewest rainy days: June, July, August and September
- Seasonal pattern: A distinct dry season from April to November, with very warm summers and pleasant winters
Frequently asked questions about the climate in San Dimas
What is the best time to visit San Dimas?
January, February, March, April, May, October and November typically offer the most optimal weather in San Dimas. In contrast, July and August tend to have less optimal conditions. San Dimas has a distinct dry season from April to November, with very warm summers and pleasant winters.
What temperatures can I expect in San Dimas?
Daytime highs range from 19°C (66°F) in December to 33°C (91°F) in August. Nighttime lows range from 6°C (43°F) to 17°C (63°F). Temperatures vary considerably through the year.
How much rain does San Dimas get?
Annual rainfall is around 344 mm (14 in). December is the wettest month with 93 mm (3.7 in), while June is the driest with 0.2 mm (0.01 in).
How sunny is San Dimas?
San Dimas receives around 3,279 hours of sunshine per year. July is the sunniest month with 369 hours, while January is the cloudiest with just 198 hours. Overall, San Dimas enjoys abundant sunshine.
San Dimas 3-Day Forecast
San Dimas on the map
San Dimas is highlighted - select any city to see its climate.
Popular this month
Where to go in September - average daytime high across popular destinations.
Bucket list
Need travel inspiration? Check out our bucket list articles and be inspired.
Yosemite National Park is definitely worth a visit
Vast forests, blue lakes, towering sequoias, and majestic waterfalls hint at the beauty of Yosemite National Park—a true natural masterpiece.
The 10 most alternative cities in the United States
Discover the top 10 fun and alternative U.S. cities rich in art, culture, and adventure. From Portland's hippy charm to Sedona's stunning landscapes.
Sedona: Explore Majestic Red Rock Landscapes
A picturesque artists' town surrounded by red rocks and known for its spirituality, vortex energy, and stunning hikes like Cathedral Rock.
10 most idyllic villages to visit in the United States
Discover 10 idyllic villages in the USA, from California to Vermont. Explore their unique charm, rich history, stunning nature, and vibrant arts scenes.