Rialto, CA All-Time Weather Extremes
The most extreme temperature, precipitation, and snowfall ever recorded in Rialto, from NOAA daily weather observations.
| Temperature | ||
|---|---|---|
| Record High | 109.9°F (43°C) | August 7, 1970 |
| Record Low | 24.9°F (-4°C) | January 3, 1970 |
| Lowest High | 48.2°F (9°C) | March 14, 2025 |
| Highest Low | 76.1°F (24°C) | July 24, 2026 |
| Highest Mean | 90.0°F (32°C) | July 24, 2026 |
| Lowest Mean | 41.4°F (5°C) | January 4, 1970 |
| Precipitation | ||
| Max in One Calendar Day | 1.32" (33.5 mm) | November 29, 1970 |
| Max in One Month | 3.29" (83.5 mm) | December 1970 |
| Least in One Month | 0.00" (0.0 mm) | May 1970 |
| Max in One Year | 12.34" (313.4 mm) | 1970 |
| Least in One Year | 12.34" (313.4 mm) | 1970 |
| Period of Record | ||
| Temperature | January 1, 1970 – July 31, 2026 | |
| Precipitation | January 1, 1970 – December 31, 1970 | |
| Snowfall | January 1, 1970 – December 31, 1970 | |
Note: Records compiled from NOAA GHCN-Daily observations at NORTON AFB (7 mi from Rialto, CA). Quality-flagged readings are excluded. Monthly and annual totals require substantially complete reporting for “least” records.
Shareable Image Version
Frequently Asked Questions
What is the hottest temperature ever recorded in Rialto, CA?
The all-time record high in Rialto, CA is 109.9°F (43°C), set on August 7, 1970.
What is the coldest temperature ever recorded in Rialto, CA?
The all-time record low in Rialto, CA is 24.9°F (-4°C), set on January 3, 1970.
What is the most rain Rialto, CA has ever had in one day?
The most precipitation recorded in one calendar day near Rialto, CA is 1.32 inches, on November 29, 1970.
Look Up Extremes by ZIP Code
See the all-time weather extremes for any US location
Rialto Weather History
Monthly averages, records, and climate data for Rialto
California Weather Extremes
Statewide records and extremes for other California cities