Castella’s winters are milder but snowier than most of the U.S.
A typical July afternoon reaches 92°, a January night drops to 30°, and about 27 inches of snow falls in a normal winter.
A year in Castella at a glance
Each month’s typical high and low, and what it brings.
What stands out about Castella’s climate
Compared with towns across the U.S., with Castella’s place in California beside it.
What a year in Castella feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 185 frost-free days a year
In half of years the last 32° night comes by April 23 and the first by October 27. Frost and day counts come from NOAA’s station at Dunsmuir Trtmt Pl, CA, 0.5 miles from the town’s center, at about the same height.
The 2023 USDA map puts Castella’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 27 inches of snow a winter
Snow, measured at Dunsmuir Trtmt Pl, CA, falls mostly in January. Precipitation (rain plus melted snow) adds up to 64 inches a year; December is the wettest month and July the driest. Rain or snow falls on about 98 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Castella
89% of the work is heating, so the furnace matters far more than the air conditioner. 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 Dunsmuir Trtmt Pl, CA.
Living with Castella’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
185 frost-free days in zone 8b. The last frost comes by Apr 23 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Oct 27.
Months with highs of 62–84° and lows of 40° or more: May and June. 0.5 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Castella from natural hazards, wildfire is the largest share (61%). Normals are averages; the hazards page covers the extremes.
Natural hazards →Castella and similar climates
TownRatings has no climate map of the towns around Castella yet.
Climates most like Castella’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 |
|---|---|---|---|---|
| Castella, CA | 30° | 92° | 64" | 27" |
| Mena, AR | 29° | 90° | 58" | 4.0" |
| Marion, NC | 28° | 88° | 58" | 7.1" |
| Winchester, TN | 29° | 88° | 59" | 4.1" |
| Bowling Green, KY | 28° | 89° | 51" | 8.5" |
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 Castella averaged 1.2° warmer than the 1900s. The biggest change is in September (+2.3°).
A smaller shift than in 64% 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 Castella compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Castella’s place among California’s.
Castella weather by month
Highs, lows and precipitation from NOAA’s grid at Castella’s center; snow, wet days and snow on the ground from Dunsmuir Trtmt Pl, CA. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 49° | 30° | 10.7" | 8.2" | 15 | 10 | 35° – 46° |
| February | 53° | 31° | 11.0" | 6.7" | 13 | 6 | 35° – 48° |
| March | 58° | 33° | 9.7" | 2.7" | 13 | 2 | 39° – 52° |
| April | 64° | 36° | 4.8" | 0.6" | 11 | 0 | 45° – 55° |
| May | 74° | 43° | 2.8" | 0.0" | 8 | 0 | 51° – 65° |
| June | 83° | 49° | 1.3" | 0.0" | 4 | 0 | 61° – 72° |
| July | 92° | 54° | 0.1" | 0.0" | 1 | 0 | 68° – 77° |
| August | 91° | 52° | 0.2" | 0.0" | 1 | 0 | 69° – 76° |
| September | 85° | 46° | 0.7" | 0.0" | 2 | 0 | 63° – 69° |
| October | 72° | 39° | 3.2" | 0.0" | 6 | 0 | 51° – 60° |
| November | 57° | 33° | 7.4" | 1.7" | 10 | 1 | 36° – 49° |
| December | 48° | 29° | 12.4" | 6.8" | 14 | 6 | 35° – 43° |
| Year | 69° | 39° | 64.3" | 26.7" | 98 | 26 |
How much a month can swing
A normal is an average. May swings the most: from 1991 to 2020 its average ranged from 51° to 65°. September is the most reliable, staying within 7°.
Where Castella’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 Castella’s center.
- Snow: Dunsmuir Trtmt Pl, CA (NOAA station in town).
- Frost, freezing nights, 90° and 100° days, heating and cooling: Dunsmuir Trtmt Pl, CA, 0.5 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 Castella’s climate
What is the weather like in Castella?
A typical July afternoon reaches 92°, a January night drops to 30°, and about 27 inches of snow falls in a normal winter. Milder January nights than 72% of U.S. towns; hotter July afternoons than 87% of U.S. towns.
How cold does it get in Castella in winter?
December nights average 29°. About 105 nights a year reach 32° or below. In the coldest December of the last 30 years the month averaged 35°.
How much snow does Castella get?
About 27 inches in a normal winter at Dunsmuir Trtmt Pl, CA, most of it in January, with snow on the ground about 26 days a year.
How hot does it get in Castella?
July, with a typical high of 92° and a low of 54°. About 59 days a year reach 90° and 6 reach 100° (Dunsmuir Trtmt Pl, CA).
When is the first and last frost in Castella?
In half of years the last spring frost (32°) comes by April 23 and the first fall frost by October 27, about 185 frost-free days, at Dunsmuir Trtmt Pl, CA.
What growing zone is Castella 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 Castella?
By one simple rule (highs of 62–84° and lows of 40° or more), May and June. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Castella getting warmer?
Yes: 1991–2020 averaged 1.2° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 64% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Castella.
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.