Alta is among the wettest of U.S. towns: 63 inches of precipitation a year
On a normal July day the thermometer tops out near 87°. December is the wettest month, July the driest. Winters are mild: January nights here are milder than in 78% of U.S. towns. If you like long walks, May, June, September and October offer highs of 69–82°.
A year in Alta at a glance
Each month’s typical high and low, and what it brings.
What stands out about Alta’s climate
Compared with towns across the U.S., with Alta’s place in California beside it.
What a year in Alta feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 221 frost-free days a year
In half of years the last 32° night comes by April 12 and the first by November 21. Frost and day counts come from Georgetown Rs, CA, 20 miles away.
The 2023 USDA map puts Alta’s center in zone 9a: the coldest night of a typical winter, averaged over 1991–2020, reaches about 20°. 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 15 inches of snow a winter
Snow, measured at Nevada City, CA, falls mostly in February. Precipitation (rain plus melted snow) adds up to 63 inches a year; December is the wettest month and July the driest. Rain or snow falls on about 85 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Alta
75% 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 Georgetown Rs, CA.
Living with Alta’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
221 frost-free days in zone 9a. The last frost comes by Apr 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 Nov 21.
Months with highs of 62–84° and lows of 40° or more: May, June, September and October. 1.7 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Alta from natural hazards, avalanches are the largest share (64%). Normals are averages; the hazards page covers the extremes.
Natural hazards →Alta and similar climates
TownRatings has no climate map of the towns around Alta yet.
Climates most like Alta’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 |
|---|---|---|---|---|
| Alta, CA | 33° | 87° | 63" | 15" |
| Fort Payne, AL | 31° | 86° | 60" | 5.0" |
| Soddy-Daisy, TN | 30° | 87° | 59" | 4.3" |
| Dahlonega, GA | 30° | 87° | 63" | 3.3" |
| Marion, NC | 28° | 88° | 58" | 7.1" |
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 Alta averaged 0.7° warmer than the 1900s. The biggest change is in September (+1.9°).
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 Alta compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Alta’s place among California’s.
Alta weather by month
Highs, lows and precipitation from NOAA’s grid at Alta’s center; snow, wet days and snow on the ground from Nevada City, CA. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 50° | 33° | 11.0" | 2.3" | 14 | 2 | 36° – 49° |
| February | 51° | 34° | 10.4" | 4.6" | 12 | 4 | 34° – 50° |
| March | 55° | 36° | 9.6" | 3.2" | 12 | 3 | 36° – 54° |
| April | 61° | 39° | 5.4" | 0.9" | 9 | 1 | 42° – 54° |
| May | 69° | 45° | 3.4" | 0.0" | 6 | 0 | 47° – 65° |
| June | 79° | 52° | 1.0" | 0.0" | 3 | 0 | 60° – 71° |
| July | 87° | 59° | 0.0" | 0.0" | 0 | 0 | 68° – 77° |
| August | 87° | 58° | 0.1" | 0.0" | 1 | 0 | 69° – 76° |
| September | 82° | 52° | 0.6" | 0.0" | 2 | 0 | 62° – 72° |
| October | 70° | 45° | 3.5" | 0.0" | 4 | 0 | 53° – 65° |
| November | 56° | 37° | 6.7" | 0.8" | 9 | 1 | 38° – 53° |
| December | 48° | 33° | 11.5" | 2.7" | 12 | 2 | 36° – 46° |
| Year | 66° | 44° | 63.1" | 14.5" | 85 | 13 |
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 65°. August is the most reliable, staying within 7°.
Where Alta’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 Alta’s center.
- Snow: Nevada City, CA.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Georgetown Rs, CA, 20 miles from the town’s center, 800 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 Alta’s climate
What is the weather like in Alta?
A typical July afternoon reaches 87°, a January night drops to 33°, and about 15 inches of snow falls in a normal winter. Milder January nights than 78% of U.S. towns; hotter July afternoons than 61% of U.S. towns.
How cold does it get in Alta in winter?
December nights average 33°. About 49 nights a year reach 32° or below. In the coldest December of the last 30 years the month averaged 36°.
How much snow does Alta get?
About 15 inches in a normal winter at Nevada City, CA, most of it in February, with snow on the ground about 13 days a year.
How hot does it get in Alta?
July, with a typical high of 87° and a low of 59°. About 58 days a year reach 90° and 5 reach 100° (Georgetown Rs, CA).
When is the first and last frost in Alta?
In half of years the last spring frost (32°) comes by April 12 and the first fall frost by November 21, about 221 frost-free days, at Georgetown Rs, CA.
What growing zone is Alta in?
Zone 9a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 20°.
What is the best time of year to visit Alta?
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 Alta 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 Alta.
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.