The best times to visit San Dimas for ideal weather are

March 5th to August 5th

or

September 17th to November 18th

based on average temperature and humidity from NOAA (the National Oceanic and Atmospheric Administration). Read below for more weather and travel details.

 

 


Other San Dimas Travel Info

Weather in San Dimas

Temperature

Average temperatures in San Dimas vary greatly. Considering humidity, temperatures feel very nice much of the year, but hot in the summer and cold in the winter with a very low chance of rain or snow throughout the year. The area is somewhat temperate — in the 55th percentile for pleasant weather — compared to tourist destinations worldwide. Weeks with ideal weather are listed above. If you’re looking for the very warmest time to visit San Dimas, the hottest months are August, July, and then September. See average monthly temperatures below. The warmest time of year is generally late August to early September where highs are regularly around 99°F (37.2°C) with temperatures rarely dropping below 63.4°F (17.4°C) at night.

San Dimas Temperatures (Fahrenheit)

Key
High
Average
Low

San Dimas Temperatures (Celsius)

Key
High
Average
Low

“Feels-Like” Temperatures

The way we experience weather isn’t all about temperature. Higher temperatures affect us much more at higher humidity, and colder temperatures feel piercing with high winds. Our perceived temperatures factor in humidity and wind chill to better represent how hot or cold the day feels to a person.

San Dimas Perceived Temperature (F)

Key
High
Average
Low

San Dimas Perceived Temperature (C)

Key
High
Average
Low

 

Average San Dimas Temperatures by Month

Daily highs (averaged for the month) usually give the best indication of the weather. A significantly lower mean and low generally just means it gets colder at night.

Show Fahrenheit

Month Avg. High (°F) Avg. Mean (°F) Avg. Low (°F)
Jan 71 54.5 39.4
Feb 70 54.3 40.7
Mar 75.2 58.5 44.1
Apr 77.9 61.1 46.8
May 82 65.4 52.1
Jun 87.9 70 56.4
Jul 92.8 75 61.2
Aug 95.7 76.5 61.3
Sep 94.2 74.4 59.4
Oct 85.4 67 52.3
Nov 76.9 58.8 43.6
Dec 67.9 52.3 39.2

Show Celsius

Month Avg. High (°C) Avg. Mean (°C) Avg. Low (°C)
Jan 21.7 12.5 4.1
Feb 21.1 12.4 4.8
Mar 24 14.7 6.7
Apr 25.5 16.2 8.2
May 27.8 18.6 11.2
Jun 31.1 21.1 13.6
Jul 33.8 23.9 16.2
Aug 35.4 24.7 16.3
Sep 34.6 23.6 15.2
Oct 29.7 19.4 11.3
Nov 24.9 14.9 6.4
Dec 19.9 11.3 4

 


 

Precipitation (Rain or Snow)

If dry weather is what you’re after, the months with the lowest chance of significant precipitation in San Dimas are June, August, and then July. Note that we define “significant precipitation” as .1 inches or more in this section. The lowest chance of rain or snow occurs around early April. For example, on the week of April 2nd there are no days of precipitation on average. By contrast, it’s most likely to rain or snow in mid December with an average of 1 days of significant precipitation the week of December 17th.

When can you find snow in San Dimas? Weather stations report no annual snow. Please note that a value of 0 for snow in the graph below may either mean there was no snow, or that snow is unreported.

Chance of Precipitation

The graph below shows the % chance of rainy and snowy days in San Dimas.

Key
Days with precipitation

Snow on the Ground

The graph below shows the average snow on the ground in San Dimas (in).

Key
Snow depth

Average Rain and Snow by Month

Show Inches

Month Daily Chance of Rain Average Snow Depth (in) Total Precipitation (in)
Jan 8% 0 1
Feb 11% 0 1.3
Mar 5% 0 0.5
Apr 2% 0 0.3
May 2% 0 0.2
Jun 0% 0 0
Jul 1% 0 0.1
Aug 0% 0 0
Sep 1% 0 0.1
Oct 3% 0 0.4
Nov 3% 0 0.5
Dec 13% 0 2.1

Show Centimeters

Month Daily Chance of Rain Average Snow Depth (cm) Total Precipitation (cm)
Jan 8 0 2.5
Feb 11 0 3.3
Mar 5 0 1.3
Apr 2 0 0.8
May 2 0 0.5
Jun 0 0 0
Jul 1 0 0.3
Aug 0 0 0
Sep 1 0 0.3
Oct 3 0 1
Nov 3 0 1.3
Dec 13 0 5.3

 

Humidity and Wind

San Dimas has some comfortably humid months, with slightly drier months on the other side of the year. The least humid month is January (43% relative humidity), and the most humid month is February (54.1%).

Wind in San Dimas is usually calm. The windiest month is May, followed by June and July. May’s average wind speed of around 5.7 knots (6.6 MPH or 10.6 KPH) is considered “a light breeze.” Maximum sustained winds (the highest speed for the day lasting more than a few moments) are at their highest in early May where average top sustained speeds reach 15.5 knots, which is considered a moderate breeze.

Relative Humidity (%)

The graph below shows the average % humidity by month in San Dimas.

Key
Avg. Relative Humidity

Wind

The graph below shows wind speed (max and average) in knots.

Key
Max Sustained Wind
Average Daily Wind

Average Wind Speeds

Show Wind Speeds

All wind speeds are in knots. 1 knot = 1.15 MPH or 1.85 KPH.

Month Avg. Wind Avg. Wind Feel Sustained High Wind High Wind Feel
Jan 3.6 Barely noticeable 11 Significant breeze
Feb 3.5 Barely noticeable 11.6 Significant breeze
Mar 4.3 Light breeze 13.1 Significant breeze
Apr 5.3 Light breeze 14.6 Significant breeze
May 5.7 Light breeze 14.7 Significant breeze
Jun 5.6 Light breeze 14.5 Significant breeze
Jul 5.5 Light breeze 14.3 Significant breeze
Aug 5 Light breeze 14 Significant breeze
Sep 4.3 Light breeze 13.4 Significant breeze
Oct 3.9 Barely noticeable 12.2 Significant breeze
Nov 3.2 Barely noticeable 10.5 Significant breeze
Dec 2.8 Barely noticeable 9.4 Gentle breeze

Show Relative Humidity by Month

Month Avg. Relative Humidity
Jan 43%
Feb 54.1%
Mar 49.8%
Apr 46.8%
May 48.3%
Jun 49.2%
Jul 46.9%
Aug 43.2%
Sep 44%
Oct 45.9%
Nov 45.6%
Dec 52.2%

 

Is it Safe to Travel to San Dimas?

Our best data indicates this area is generally safe. As of Dec 04, 2023 there are no travel advisories or warnings for the United States; exercise normal security precautions. Check this page for any recent changes or regions to avoid: Travel Advice and Advisories. This advisory was last updated on Dec 04, 2023.


 

The Busiest and Least Crowded Months

The busiest month for tourism in San Dimas, CA, US is July, followed by June and May. Prices for hotels and flights will be most expensive during these months, though you can save if you purchase well in advance. Tourists are unlikely to visit San Dimas in December. Those willing to visit at these times will likely find it the least expensive month.

Estimated Tourism by Month

 

Most Popular Months to Visit

Key
Tourists Seeking Accommodations

Tourism graph is based on Google searches for services used by tourists relative to the rest of the year. Tourism data for this area is very reliable. Displayed data is calculated relative to the peak, so a score of 67.6 in December means 67.6% of the tourists vs. July.

 

 

Overall San Dimas Travel Experience by Season

Spring (March through May)

Humidity and temperatures combine to make this season feel moderate. Highs range from 84.4°F (29.1°C) and 70°F (21.1°C) with warmer temperatures in the later months. Rain is rare with roughly 1 days of significant precipitation per month. Spring is the second busiest for tourism, which makes it a good time for those looking for things to do.

Summer (June through August)

The middle-year months have very comfortable weather with high temperatures that are quite warm. These months see the least precipitation with about 0 days of precipitation per month. June – August is the busiest season for tourism in San Dimas, so lodging and other accommodations may cost more than usual.

Fall (September through November)

Fall daily highs range from 96.7°F (35.9°C) and 73.4°F (23°C), which will feel very nice given the humidity and wind. It rains or snows a barely noticeable amount: 0 to 1 days per month. Tourism is the slowest during these months due to the weather, so hotels may be affordably priced.

Winter (December through February)

Weather is too cold this time of year in San Dimas to be enjoyable for warm weather travelers. The average high during this season is between 72.6°F (22.6°C) and 65.6°F (18.7°C). On average, it rains or snows a smalll amount: 2 to 4 times per month. These times of year are fairly slow with tourists.

 

Best Times to Travel› the United States › San Dimas, CA, US