Ash Mountain Entrance Sign · Photo: Brian C. Grogan · Public domainThree Rivers reaches 100° on about 42 days a year, more than 98% of U.S. towns
A typical July afternoon reaches 98°, a January night drops to 36°, and snow is almost unheard of.
A year in Three Rivers at a glance
Each month’s typical high and low, and what it brings.
What stands out about Three Rivers’ climate
Compared with towns across the U.S., with Three Rivers’ place in California beside it.
What a year in Three Rivers feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 273 frost-free days a year
In half of years the last 32° night comes by March 12 and the first by December 9. Frost and day counts come from NOAA’s station at Ash Mtn, CA, 5 miles from the town’s center, 140 ft higher.
The 2023 USDA map puts Three Rivers’ center in zone 10a: the coldest night of a typical winter, averaged over 1991–2020, reaches about 30°. 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 19 inches of rain a year
January is the wettest month and August the driest. Rain falls on about 51 days a year. Snow is rare: about 0.0" in a normal year at Three Rivers Edison Ph 1, CA, so most winters see none.
Rain + melted snow by month
Inches of water
Heating and cooling a home in Three Rivers
56% of the work is heating. Months averaging under 55° run from November through February.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Ash Mtn, CA.
Living with Three Rivers’ climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
273 frost-free days in zone 10a. The last frost comes by Mar 12 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Dec 9.
Months with highs of 62–84° and lows of 40° or more: March, April, May, October and November. 13 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Three Rivers from natural hazards, river flooding is the largest share (47%); heat waves, cold waves, winter storms and ice storms together are 2%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Three Rivers and similar climates
TownRatings has no climate map of the towns around Three Rivers yet.
Climates most like Three Rivers’, 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 |
|---|---|---|---|---|
| Three Rivers, CA | 36° | 98° | 19" | 0.0" |
| Del Rio, TX | 40° | 98° | 19" | 0.2" |
| Catalina, AZ | 35° | 98° | 14" | 0.0" |
| Ivins, UT | 32° | 100° | 11" | 1.2" |
| Carlsbad, NM | 29° | 97° | 13" | 2.7" |
Temperatures and precipitation come from NOAA’s 5 km grid; snow and day counts from the stations named on this page.
Warmer than it used to be
The last 30 years in Three Rivers averaged 1.7° warmer than the 1900s. The biggest change is in September (+2.5°).
A bigger shift than in 69% 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 Three Rivers compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Three Rivers’ place among California’s.
Three Rivers weather by month
Highs, lows and precipitation from NOAA’s grid at Three Rivers’ center; snow, wet days and snow on the ground from Three Rivers Edison Ph 1, CA. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 59° | 36° | 3.8" | 0.0" | 8 | 0 | 43° – 54° |
| February | 63° | 39° | 3.5" | 0.0" | 9 | 0 | 45° – 58° |
| March | 69° | 42° | 3.1" | 0.0" | 8 | 0 | 48° – 63° |
| April | 74° | 45° | 1.8" | 0.0" | 6 | 0 | 55° – 65° |
| May | 83° | 52° | 1.0" | 0.0" | 3 | 0 | 58° – 75° |
| June | 92° | 59° | 0.2" | 0.0" | 1 | 0 | 69° – 80° |
| July | 98° | 65° | 0.0" | 0.0" | 1 | 0 | 78° – 85° |
| August | 98° | 64° | 0.0" | 0.0" | 0 | 0 | 77° – 84° |
| September | 92° | 58° | 0.1" | 0.0" | 1 | 0 | 71° – 79° |
| October | 81° | 49° | 1.0" | 0.0" | 3 | 0 | 61° – 71° |
| November | 67° | 41° | 1.6" | 0.0" | 5 | 0 | 46° – 59° |
| December | 58° | 36° | 2.9" | 0.0" | 8 | 0 | 44° – 52° |
| Year | 78° | 49° | 19.1" | 0.0" | 51 | 0 |
How much a month can swing
A normal is an average. May swings the most: from 1991 to 2020 its average ranged from 58° to 75°. August is the most reliable, staying within 7°.
Where Three Rivers’ 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 Three Rivers’ center.
- Snow: Three Rivers Edison Ph 1, CA.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Ash Mtn, CA, 5 miles from the town’s center, 140 ft higher; 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 Three Rivers’ climate
What is the weather like in Three Rivers?
A typical July afternoon reaches 98°, a January night drops to 36°, and snow is almost unheard of. Milder January nights than 83% of U.S. towns; hotter July afternoons than 98% of U.S. towns.
How cold does it get in Three Rivers in winter?
December nights average 36°. About 23 nights a year reach 32° or below. In the coldest December of the last 30 years the month averaged 44°.
How much snow does Three Rivers get?
About 0.0 inches in a normal winter at Three Rivers Edison Ph 1, CA, so most winters see none.
How hot does it get in Three Rivers?
July, with a typical high of 98° and a low of 65°. About 112 days a year reach 90° and 42 reach 100° (Ash Mtn, CA).
When is the first and last frost in Three Rivers?
In half of years the last spring frost (32°) comes by March 12 and the first fall frost by December 9, about 273 frost-free days, at Ash Mtn, CA.
What growing zone is Three Rivers in?
Zone 10a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 30°.
What is the best time of year to visit Three Rivers?
By one simple rule (highs of 62–84° and lows of 40° or more), March, April, May, October and November. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Three Rivers getting warmer?
Yes: 1991–2020 averaged 1.7° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 69% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Three Rivers.
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.