Photo: Chuffmire · CC BY-SA 4.0Midwinter lows in Rancho Santa Margarita stay above those of 95% of U.S. towns
On a normal July day the thermometer tops out near 86°. It is a dry place: less rain and snow fall here than on 95% of U.S. towns. Compared with 1901–2000, the average now sits 2.0° higher. Garden chairs stay out from October to June, the months with highs of 67–80°.
A year in Rancho Santa Margarita at a glance
Each month’s typical high and low, and what it brings.
What stands out about Rancho Santa Margarita’s climate
Compared with towns across the U.S., with Rancho Santa Margarita’s place in California beside it.
What a year in Rancho Santa Margarita feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
Frost is rare
Frost and day counts come from NOAA’s station at Irvine Rch, CA, 9 miles from the town’s center, 420 ft lower.
The 2023 USDA map puts Rancho Santa Margarita’s center in zone 10b: the coldest night of a typical winter, averaged over 1991–2020, reaches about 38°. Plant labels use the zone; frost dates tell you when to plant.
90° days by month
Average days at 90° or more
About 13 inches of rain a year
February is the wettest month and August the driest. Rain falls on about 32 days a year. Snow is rare: about 0.0" in a normal year at Tustin Irvine Rch, CA, so most winters see none.
Rain + melted snow by month
Inches of water
Heating and cooling a home in Rancho Santa Margarita
37% 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 Irvine Rch, CA.
Living with Rancho Santa Margarita’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
Zone 10b. Frost comes about 1 winter in 28, so tender plants can often stay out through winter.
Months with highs of 62–84° and lows of 40° or more: January, February, March, April, May, June, October, November and December. 42 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Rancho Santa Margarita from natural hazards, river flooding is the largest share (51%); heat waves, cold waves, winter storms and ice storms together are 1%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Rancho Santa Margarita and its neighbors
Trabuco Canyon the hottest July afternoons (87°, 1° 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 Rancho Santa Margarita’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 |
|---|---|---|---|---|
| Rancho Santa Margarita, CA | 47° | 86° | 13" | 0.0" |
| Ewa Beach, HI | 62° | 87° | 17" | 0.0" |
| Port Isabel, TX | 52° | 92° | 26" | 0.2" |
| Sierra Vista Southeast, AZ | 32° | 91° | 15" | 0.7" |
| The Dalles, OR | 31° | 88° | 15" | 5.5" |
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 Rancho Santa Margarita averaged 2.0° warmer than the 1900s. The biggest change is in January (+3.2°).
A bigger shift than in 91% of 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 Rancho Santa Margarita compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Rancho Santa Margarita’s place among California’s.
Rancho Santa Margarita weather by month
Highs, lows and precipitation from NOAA’s grid at Rancho Santa Margarita’s center; snow, wet days and snow on the ground from Tustin Irvine Rch, CA. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 67° | 47° | 2.8" | 0.0" | 6 | 0 | 53° – 63° |
| February | 67° | 47° | 3.4" | 0.0" | 7 | 0 | 50° – 65° |
| March | 69° | 48° | 2.0" | 0.0" | 5 | 0 | 52° – 66° |
| April | 72° | 50° | 0.8" | 0.0" | 3 | 0 | 57° – 65° |
| May | 75° | 53° | 0.3" | 0.0" | 2 | 0 | 59° – 70° |
| June | 80° | 57° | 0.1" | 0.0" | 0 | 0 | 65° – 73° |
| July | 86° | 62° | 0.0" | 0.0" | 0 | 0 | 71° – 80° |
| August | 88° | 63° | 0.0" | 0.0" | 0 | 0 | 72° – 79° |
| September | 86° | 61° | 0.1" | 0.0" | 0 | 0 | 70° – 78° |
| October | 79° | 56° | 0.5" | 0.0" | 2 | 0 | 63° – 73° |
| November | 73° | 51° | 0.9" | 0.0" | 3 | 0 | 56° – 66° |
| December | 67° | 46° | 2.1" | 0.0" | 5 | 0 | 53° – 63° |
| Year | 76° | 53° | 13.0" | 0.0" | 32 | 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 65°. August is the most reliable, staying within 7°.
Where Rancho Santa Margarita’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 Rancho Santa Margarita’s center.
- Snow: Tustin Irvine Rch, CA.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Irvine Rch, CA, 9 miles from the town’s center, 420 ft lower; 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 Rancho Santa Margarita’s climate
What is the weather like in Rancho Santa Margarita?
A typical July afternoon reaches 86°, a January night drops to 47°, and snow is almost unheard of. Milder January nights than 95% of U.S. towns; hotter July afternoons than 54% of U.S. towns.
How cold does it get in Rancho Santa Margarita in winter?
December nights average 46°. A night at 32° or below comes in only some winters (0.7 a year on average). In the coldest December of the last 30 years the month averaged 53°.
How much snow does Rancho Santa Margarita get?
About 0.0 inches in a normal winter at Tustin Irvine Rch, CA, so most winters see none.
How hot does it get in Rancho Santa Margarita?
July, with a typical high of 86° and a low of 62°. About 62 days a year reach 90° and 8 reach 100° (Irvine Rch, CA).
When is the first and last frost in Rancho Santa Margarita?
Most years have no frost at all: a 32° night comes in about 4% of winters at Irvine Rch, CA, usually in December or January.
What growing zone is Rancho Santa Margarita in?
Zone 10b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 38°.
What is the best time of year to visit Rancho Santa Margarita?
By one simple rule (highs of 62–84° and lows of 40° or more), January, February, March, April, May, June, October, November and December. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Rancho Santa Margarita getting warmer?
Yes: 1991–2020 averaged 2.0° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 91% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Rancho Santa Margarita.
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.