Photo: Missvain · CC BY 4.0Summer arrives in force in Calpella, hotter than in 85% of U.S. towns
Nights in January average 36°. Temperatures cover 56° across the year, low to high. Winters are mild: January nights here are milder than in 82% of U.S. towns. The heating season runs December to February: each of those months averages under 50°.
A year in Calpella at a glance
Each month’s typical high and low, and what it brings.
What stands out about Calpella’s climate
Compared with towns across the U.S., with Calpella’s place in California beside it.
What a year in Calpella feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 245 frost-free days a year
In half of years the last 32° night comes by March 19 and the first by November 20. Frost and day counts come from NOAA’s station at Ukiah, CA, 6 miles from the town’s center, 160 ft lower.
The 2023 USDA map puts Calpella’s center in zone 9a: the coldest night of a typical winter, averaged over 1991–2020, reaches about 22°. 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 3 inches of snow a winter
Snow, measured at Ukiah 4 Wsw, CA, falls mostly in February. Precipitation (rain plus melted snow) adds up to 36 inches a year; December is the wettest month and July the driest. Rain or snow falls on about 99 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Calpella
78% 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 Ukiah, CA.
Living with Calpella’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
245 frost-free days in zone 9a. The last frost comes by Mar 19 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 20.
Months with highs of 62–84° and lows of 40° or more: April, May, June and October. 5.2 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Calpella from natural hazards, river flooding is the largest share (65%). Normals are averages; the hazards page covers the extremes.
Natural hazards →Calpella and similar climates
TownRatings has no climate map of the towns around Calpella yet.
Climates most like Calpella’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 |
|---|---|---|---|---|
| Calpella, CA | 36° | 92° | 36" | 2.5" |
| Grants Pass, OR | 34° | 90° | 33" | 0.9" |
| Boerne, TX | 39° | 93° | 33" | 0.1" |
| Lugoff, SC | 33° | 92° | 43" | 0.4" |
| Monroe, NC | 31° | 91° | 43" | 2.1" |
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 Calpella averaged 0.7° warmer than the 1900s. The biggest change is in January (+1.4°).
A smaller shift than in 93% 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 Calpella compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Calpella’s place among California’s.
Calpella weather by month
Highs, lows and precipitation from NOAA’s grid at Calpella’s center; snow, wet days and snow on the ground from Ukiah 4 Wsw, CA. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 57° | 36° | 7.1" | 0.3" | 17 | 0 | 43° – 51° |
| February | 60° | 37° | 6.5" | 1.2" | 15 | 0 | 43° – 55° |
| March | 64° | 39° | 5.2" | 0.6" | 14 | 0 | 44° – 58° |
| April | 69° | 41° | 2.4" | 0.0" | 11 | 0 | 49° – 60° |
| May | 76° | 46° | 1.3" | 0.0" | 7 | 0 | 53° – 68° |
| June | 84° | 50° | 0.4" | 0.0" | 2 | 0 | 62° – 73° |
| July | 92° | 54° | 0.0" | 0.0" | 0 | 0 | 69° – 76° |
| August | 91° | 53° | 0.1" | 0.0" | 0 | 0 | 69° – 76° |
| September | 87° | 49° | 0.2" | 0.0" | 1 | 0 | 65° – 72° |
| October | 77° | 44° | 1.7" | 0.0" | 5 | 0 | 57° – 68° |
| November | 63° | 39° | 3.8" | 0.1" | 11 | 0 | 44° – 56° |
| December | 55° | 35° | 7.3" | 0.3" | 16 | 0 | 42° – 49° |
| Year | 73° | 44° | 35.9" | 2.5" | 99 | 1 |
How much a month can swing
A normal is an average. May swings the most: from 1991 to 2020 its average ranged from 53° to 68°. August is the most reliable, staying within 7°.
Where Calpella’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 Calpella’s center.
- Snow: Ukiah 4 Wsw, CA.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Ukiah, CA, 6 miles from the town’s center, 160 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 Calpella’s climate
What is the weather like in Calpella?
A typical July afternoon reaches 92°, a January night drops to 36°, and about 3 inches of snow falls in a normal winter. Milder January nights than 82% of U.S. towns; hotter July afternoons than 85% of U.S. towns.
How cold does it get in Calpella in winter?
December nights average 35°. About 34 nights a year reach 32° or below. In the coldest December of the last 30 years the month averaged 42°.
How much snow does Calpella get?
About 2.5 inches in a normal winter at Ukiah 4 Wsw, CA, most of it in February, with snow on the ground about 1 days a year.
How hot does it get in Calpella?
July, with a typical high of 92° and a low of 54°. About 61 days a year reach 90° and 9 reach 100° (Ukiah, CA).
When is the first and last frost in Calpella?
In half of years the last spring frost (32°) comes by March 19 and the first fall frost by November 20, about 245 frost-free days, at Ukiah, CA.
What growing zone is Calpella in?
Zone 9a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 22°.
What is the best time of year to visit Calpella?
By one simple rule (highs of 62–84° and lows of 40° or more), April, May, June and October. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Calpella getting warmer?
Yes: 1991–2020 averaged 0.7° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 93% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Calpella.
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.