Twain Harte has milder winter nights than 76% of U.S. towns
Midsummer highs settle at about 88°. Its July heat outdoes that of 69% of U.S. towns. The latest 30-year average runs 0.9° warmer than 1901–2000’s, with January up the most. The heating season runs November to April: each of those months averages under 50°.
A year in Twain Harte at a glance
Each month’s typical high and low, and what it brings.
What stands out about Twain Harte’s climate
Compared with towns across the U.S., with Twain Harte’s place in California beside it.
What a year in Twain Harte feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 192 frost-free days a year
In half of years the last 32° night comes by April 22 and the first by November 2. Frost and day counts come from Groveland 2, CA, 13 miles away.
The 2023 USDA map puts Twain Harte’s center in zone 8b: the coldest night of a typical winter, averaged over 1991–2020, reaches about 17°. 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 43 inches of rain a year
January is the wettest month and August the driest. Rain falls on about 64 days a year. Snow is rare: about 0.0" in a normal year at Sonora, CA, so most winters see none.
Rain + melted snow by month
Inches of water
Heating and cooling a home in Twain Harte
84% of the work is heating. Months averaging under 55° run from November through April.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Groveland 2, CA.
Living with Twain Harte’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
192 frost-free days in zone 8b. The last frost comes by Apr 22 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Nov 2.
Months with highs of 62–84° and lows of 40° or more: May, June, September and October. 1.0 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Twain Harte from natural hazards, wildfire is the largest share (57%); heat waves, cold waves, winter storms and ice storms together are 4%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Twain Harte and its neighbors
Mono Vista the hottest July afternoons (90°, 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 Twain Harte’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 |
|---|---|---|---|---|
| Twain Harte, CA | 33° | 88° | 43" | 0.0" |
| Rock Hill, SC | 31° | 90° | 44" | 0.2" |
| Pineville, NC | 31° | 90° | 44" | 0.2" |
| Thomson, GA | 35° | 91° | 46" | 0.5" |
| Hampton, VA | 32° | 89° | 47" | 2.7" |
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 Twain Harte averaged 0.9° warmer than the 1900s. The biggest change is in January (+2.0°).
A smaller shift than in 84% 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 Twain Harte compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Twain Harte’s place among California’s.
Twain Harte weather by month
Highs, lows and precipitation from NOAA’s grid at Twain Harte’s center; snow, wet days and snow on the ground from Sonora, CA. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 52° | 33° | 7.9" | 0.0" | 10 | 0 | 38° – 48° |
| February | 54° | 33° | 7.1" | 0.0" | 10 | 0 | 38° – 50° |
| March | 58° | 35° | 6.9" | 0.0" | 10 | 0 | 38° – 53° |
| April | 62° | 38° | 3.6" | 0.0" | 6 | 0 | 44° – 55° |
| May | 71° | 44° | 2.1" | 0.0" | 4 | 0 | 49° – 65° |
| June | 81° | 50° | 0.6" | 0.0" | 1 | 0 | 60° – 71° |
| July | 88° | 57° | 0.1" | 0.0" | 0 | 0 | 69° – 77° |
| August | 88° | 56° | 0.0" | 0.0" | 1 | 0 | 69° – 76° |
| September | 83° | 53° | 0.3" | 0.0" | 1 | 0 | 63° – 72° |
| October | 72° | 45° | 2.3" | 0.0" | 4 | 0 | 55° – 66° |
| November | 59° | 37° | 4.3" | 0.0" | 7 | 0 | 39° – 54° |
| December | 51° | 32° | 7.3" | 0.0" | 10 | 0 | 37° – 47° |
| Year | 68° | 43° | 42.6" | 0.0" | 64 | 0 |
How much a month can swing
A normal is an average. May swings the most: from 1991 to 2020 its average ranged from 49° to 65°. August is the most reliable, staying within 8°.
Where Twain Harte’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 Twain Harte’s center.
- Snow: Sonora, CA.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Groveland 2, CA, 13 miles from the town’s center, 900 ft lower; no station nearby passes every check; this is the nearest one in the same valley, flagged above.
- 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 Twain Harte’s climate
What is the weather like in Twain Harte?
A typical July afternoon reaches 88°, a January night drops to 33°, and snow is almost unheard of. Milder January nights than 76% of U.S. towns; hotter July afternoons than 69% of U.S. towns.
How cold does it get in Twain Harte in winter?
December nights average 32°. About 91 nights a year reach 32° or below. In the coldest December of the last 30 years the month averaged 37°.
How much snow does Twain Harte get?
About 0.0 inches in a normal winter at Sonora, CA, so most winters see none.
How hot does it get in Twain Harte?
July, with a typical high of 88° and a low of 57°. About 59 days a year reach 90° and 4 reach 100° (Groveland 2, CA).
When is the first and last frost in Twain Harte?
In half of years the last spring frost (32°) comes by April 22 and the first fall frost by November 2, about 192 frost-free days, at Groveland 2, CA.
What growing zone is Twain Harte in?
Zone 8b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 17°.
What is the best time of year to visit Twain Harte?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June, September and October. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Twain Harte getting warmer?
Yes: 1991–2020 averaged 0.9° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 84% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Twain Harte.
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.