Photo: Rdt8888 · Public domainNorco reaches 100° on about 23 days a year, more than 97% of U.S. towns
A typical July afternoon reaches 92°, a January night drops to 43°, and snow is almost unheard of.
A year in Norco at a glance
Each month’s typical high and low, and what it brings.
What stands out about Norco’s climate
Compared with towns across the U.S., with Norco’s place in California beside it.
What a year in Norco feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 23 days a year reach 100°
And 99 days reach 90°. Frost and day counts come from NOAA’s station at Chino Airport, 6 miles from the town’s center, at about the same height.
The 2023 USDA map puts Norco’s center in zone 10a: the coldest night of a typical winter, averaged over 1991–2020, reaches about 31°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
About 12 inches of rain a year
February is the wettest month and June the driest. Rain falls on about 28 days a year. Snow is rare: about 0.0" in a normal year at Riverside Fire Stn 3, CA, so most winters see none.
Rain + melted snow by month
Inches of water
Heating and cooling a home in Norco
43% of the work is heating, so air conditioning is the bigger bill. No month averages under 55°.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Chino Airport.
Living with Norco’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
Zone 10a. Frost comes about 9 winters in 10, so the growing year is set by heat, not cold: 23 days at 100° make midsummer the hard season for gardens.
Months with highs of 62–84° and lows of 40° or more: January, February, March, April, May, October, November and December. 73 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Norco from natural hazards, river flooding is the largest share (56%); heat waves, cold waves, winter storms and ice storms together are 1%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Norco and its neighbors
Riverside the hottest July afternoons (94°, 2° warmer). Differences under a degree are within what the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Norco’s, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| Norco, CA | 43° | 92° | 12" | 0.0" |
| Corona de Tucson, AZ | 36° | 96° | 14" | 0.1" |
| Fort Stockton, TX | 33° | 96° | 13" | 1.4" |
| Santa Teresa, NM | 33° | 95° | 9" | 2.0" |
| Ashland, OR | 31° | 91° | 19" | 0.5" |
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value. Snow and frost-free days come from the nearest weather station, so neighbors often share them.
Warmer than it used to be
The last 30 years in Norco averaged 2.4° warmer than the 1900s. The biggest change is in January (+3.3°).
A bigger shift than in all but 122 U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How Norco compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Norco’s place among California’s.
Norco weather by month
Highs, lows and precipitation from NOAA’s grid at Norco’s center; snow, wet days and snow on the ground from Riverside Fire Stn 3, CA. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 69° | 43° | 2.5" | 0.0" | 5 | 0 | 52° – 62° |
| February | 70° | 44° | 3.0" | 0.0" | 6 | 0 | 50° – 67° |
| March | 72° | 46° | 1.7" | 0.0" | 5 | 0 | 53° – 66° |
| April | 77° | 49° | 0.7" | 0.0" | 2 | 0 | 58° – 67° |
| May | 80° | 54° | 0.3" | 0.0" | 2 | 0 | 62° – 73° |
| June | 86° | 58° | 0.0" | 0.0" | 0 | 0 | 67° – 77° |
| July | 92° | 62° | 0.0" | 0.0" | 1 | 0 | 73° – 83° |
| August | 94° | 63° | 0.1" | 0.0" | 0 | 0 | 75° – 82° |
| September | 91° | 60° | 0.1" | 0.0" | 0 | 0 | 72° – 79° |
| October | 83° | 54° | 0.5" | 0.0" | 1 | 0 | 64° – 74° |
| November | 76° | 47° | 0.9" | 0.0" | 2 | 0 | 54° – 66° |
| December | 68° | 42° | 2.0" | 0.0" | 4 | 0 | 51° – 61° |
| Year | 80° | 52° | 11.7" | 0.0" | 28 | 0 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 50° to 67°. August is the most reliable, staying within 7°.
Where Norco’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at Norco’s center.
- Snow: Riverside Fire Stn 3, CA.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Chino Airport, 6 miles from the town’s center, at about the same height; the nearest station that passes our checks for distance, height and agreement with the grid.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about Norco’s climate
What is the weather like in Norco?
A typical July afternoon reaches 92°, a January night drops to 43°, and snow is almost unheard of. Milder January nights than 92% of U.S. towns; hotter July afternoons than 87% of U.S. towns.
How cold does it get in Norco in winter?
December nights average 42°. About 11 nights a year reach 32° or below. In the coldest December of the last 30 years the month averaged 51°.
How much snow does Norco get?
About 0.0 inches in a normal winter at Riverside Fire Stn 3, CA, so most winters see none.
How hot does it get in Norco?
July, with a typical high of 92° and a low of 62°. About 99 days a year reach 90° and 23 reach 100° (Chino Airport).
When is the first and last frost in Norco?
There is no reliable frost date: a 32° night comes in about 85% of winters at Chino Airport, so most years bring a freeze but some pass without one.
What growing zone is Norco in?
Zone 10a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 31°.
What is the best time of year to visit Norco?
By one simple rule (highs of 62–84° and lows of 40° or more), January, February, March, April, May, October, November and December. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Norco getting warmer?
Yes: 1991–2020 averaged 2.4° warmer than 1901–2000 on NOAA’s grid. A bigger shift than all but 122 U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Norco.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.