Summers, winters and rain in Twain all run close to those of most U.S. towns
Sunny July days climb to about 89°. By July afternoons alone, it runs hotter than 70% of U.S. towns. Since 1901–2000, the year has warmed by 1.0°, most of all in January. Seedlings are safe outdoors from about May 28, with the first autumn frost due around September 28.
A year in Twain at a glance
Each month’s typical high and low, and what it brings.
What stands out about Twain’s climate
Compared with towns across the U.S., with Twain’s place in California beside it.
What a year in Twain feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 124 frost-free days a year
In half of years the last 32° night comes by May 28 and the first by September 28. Frost and day counts come from NOAA’s station at Chester, CA, 21 miles from the town’s center, 470 ft higher.
The 2023 USDA map puts Twain’s center in zone 8a: the coldest night of a typical winter, averaged over 1991–2020, reaches about 12°. 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 28 inches of snow a winter
Snow, measured at Quincy, CA, falls mostly in February. Precipitation (rain plus melted snow) adds up to 38 inches a year; December is the wettest month and July the driest. Rain or snow falls on about 84 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Twain
97% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from October 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 Chester, CA.
Living with Twain’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
124 frost-free days in zone 8a. The last frost comes by May 28 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Sep 28.
Months with highs of 62–84° and lows of 40° or more: May, June and September. 4.1 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Twain from natural hazards, river flooding is the largest share (59%). Normals are averages; the hazards page covers the extremes.
Natural hazards →Twain and similar climates
TownRatings has no climate map of the towns around Twain yet.
Climates most like Twain’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, CA | 27° | 89° | 38" | 28" |
| Cumberland, MD | 23° | 88° | 40" | 29" |
| Sudley, VA | 26° | 88° | 42" | 21" |
| Martinsburg, WV | 23° | 87° | 40" | 23" |
| Maplewood, MO | 24° | 89° | 42" | 17" |
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 Twain averaged 1.0° warmer than the 1900s. The biggest change is in January (+2.1°).
A smaller shift than in 75% 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 compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Twain’s place among California’s.
Twain weather by month
Highs, lows and precipitation from NOAA’s grid at Twain’s center; snow, wet days and snow on the ground from Quincy, CA. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 46° | 27° | 6.4" | 5.8" | 12 | 3 | 30° – 41° |
| February | 49° | 28° | 6.5" | 7.6" | 11 | 2 | 32° – 45° |
| March | 55° | 31° | 5.7" | 5.4" | 13 | 1 | 36° – 49° |
| April | 61° | 34° | 3.0" | 1.6" | 9 | 0 | 41° – 51° |
| May | 70° | 40° | 1.9" | 0.0" | 7 | 0 | 47° – 63° |
| June | 80° | 46° | 0.8" | 0.0" | 3 | 0 | 58° – 69° |
| July | 89° | 51° | 0.1" | 0.0" | 1 | 0 | 66° – 74° |
| August | 88° | 49° | 0.2" | 0.0" | 1 | 0 | 65° – 73° |
| September | 82° | 44° | 0.4" | 0.0" | 2 | 0 | 59° – 66° |
| October | 69° | 36° | 2.0" | 0.1" | 5 | 0 | 48° – 57° |
| November | 53° | 30° | 3.9" | 1.7" | 8 | 0 | 34° – 47° |
| December | 44° | 26° | 7.2" | 6.2" | 12 | 1 | 32° – 39° |
| Year | 65° | 37° | 38.0" | 28.4" | 84 | 7 |
How much a month can swing
A normal is an average. May swings the most: from 1991 to 2020 its average ranged from 47° to 63°. December is the most reliable, staying within 7°.
Where Twain’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’s center.
- Snow: Quincy, CA.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Chester, CA, 21 miles from the town’s center, 470 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 Twain’s climate
What is the weather like in Twain?
A typical July afternoon reaches 89°, a January night drops to 27°, and about 28 inches of snow falls in a normal winter. Milder January nights than 67% of U.S. towns; hotter July afternoons than 70% of U.S. towns.
How cold does it get in Twain in winter?
December nights average 26°. About 188 nights a year reach 32° or below. In the coldest December of the last 30 years the month averaged 32°.
How much snow does Twain get?
About 28 inches in a normal winter at Quincy, CA, most of it in February, with snow on the ground about 7 days a year.
How hot does it get in Twain?
July, with a typical high of 89° and a low of 51°. About 19 days a year reach 90° (Chester, CA).
When is the first and last frost in Twain?
In half of years the last spring frost (32°) comes by May 28 and the first fall frost by September 28, about 124 frost-free days, at Chester, CA.
What growing zone is Twain in?
Zone 8a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 12°.
What is the best time of year to visit Twain?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Twain getting warmer?
Yes: 1991–2020 averaged 1.0° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 75% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Twain.
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.