Rialto weather by month
Average highs run from 44°F in January to 81°F in July, and January nights average 29°F. It gets 38 inches of rain and melted snow a year and 22 inches of snow. Nights drop below freezing about 105 times a year. The most comfortable months are June to October.
Best time to visit Rialto
For comfortable weather, go in June to October. In those months the average high stays between 62°F and 86°F, nights average 42°F or warmer, and rain stays under 4.5 inches for the month.
Month by month
| Month | High | Low | Precip. | Snow | Wet days | Days 90°F+ | Nights below 32°F | Feels |
|---|---|---|---|---|---|---|---|---|
| January | 44°F | 29°F | 8.4 in | 3.0 in | 6 | 0 | 22 | cold |
| February | 45°F | 30°F | 9.9 in | 5.3 in | 7 | 0 | 19 | cold |
| March | 52°F | 32°F | 5.2 in | 6.7 in | 4 | 0 | 16 | cool |
| April | 60°F | 36°F | 2.8 in | 2.8 in | 3 | 0 | 11 | cool |
| May | 67°F | 41°F | 1.2 in | 0.8 in | 1 | 0 | 2 | mild days, chilly nights |
| June | 76°F | 49°F | 0.3 in | 0.0 in | 0 | 1 | 0 | warm |
| July | 81°F | 57°F | 0.1 in | 0.0 in | 1 | 5 | 0 | warm |
| August | 82°F | 57°F | 0.1 in | 0.0 in | 0 | 4 | 0 | warm |
| September | 74°F | 52°F | 0.3 in | 0.0 in | 1 | 0 | 0 | mild |
| October | 63°F | 43°F | 2.1 in | 0.0 in | 2 | 0 | 2 | mild |
| November | 52°F | 34°F | 2.4 in | 0.3 in | 2 | 0 | 11 | cool |
| December | 43°F | 29°F | 5.2 in | 3.5 in | 4 | 0 | 23 | cold |
| Year | 62°F avg | 41°F avg | 37.7 in | 22.4 in | 30 | 11 | 105 |
"Wet days" are days with at least 0.1 inch of precipitation. "Feels" is a plain-language label for the average high. Normals for 1991-2020 from NOAA NCEI, station Lake Arrowhead, CA (USC00044671), 12.5 miles from the city center. Averages describe typical conditions, not a forecast.
Sunrise, sunset and daylight in Rialto
The shortest day is December 21, with 9h 52m of daylight; the longest is June 21, with 14h 26m. The earliest sunset comes around November 29 (4:39 pm) and the latest around June 28 (8:05 pm). The sun sets after 8 pm on 39 days a year.
| On the 15th of | Sunrise | Sunset | Daylight |
|---|---|---|---|
| January | 6:55 am | 5:03 pm | 10h 08m |
| February | 6:34 am | 5:33 pm | 10h 59m |
| March | 6:59 am | 6:57 pm | 11h 57m |
| April | 6:18 am | 7:21 pm | 13h 03m |
| May | 5:47 am | 7:44 pm | 13h 56m |
| June | 5:37 am | 8:02 pm | 14h 25m |
| July | 5:49 am | 8:01 pm | 14h 12m |
| August | 6:11 am | 7:36 pm | 13h 25m |
| September | 6:33 am | 6:55 pm | 12h 23m |
| October | 6:55 am | 6:14 pm | 11h 20m |
| November | 6:22 am | 4:45 pm | 10h 23m |
| December | 6:48 am | 4:41 pm | 9h 53m |
Calculated for 2026 at the center of Rialto with NOAA's solar equations, in local clock time (Pacific Time, including daylight saving time where it applies). Times shift by a minute or two from year to year.
Is Rialto getting warmer?
The last 10 years averaged 2.7°F warmer than the 20th century. See the climate stripes for Rialto.Frequently asked questions
What is the warmest month in Rialto?
August is the warmest month, with an average high of 82°F and an average low of 57°F (NOAA 1991-2020 normals).
What is the coldest month in Rialto?
January is the coldest, with average lows of 29°F and highs of 44°F.
What is the rainiest month in Rialto?
February gets the most precipitation, 9.9 inches on average. July is the driest at 0.1 inches.
Does it snow in Rialto?
Yes. Rialto averages 22 inches of snow a year.
When is the best time to visit Rialto?
For comfortable weather, June to October. Those months average highs between 62 and 86°F with lows of 42°F or more and modest rain.
Thinking of moving to Rialto?
See what homes, rent and everyday prices cost, who lives there and how it compares with nearby cities on the full Rialto profile.
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