Kuchamaa · Photo: UncleMunkle · CC BY-SA 3.0Potrero reaches 100° on about 18 days a year, more than 95% of U.S. towns
On a normal January night the air cools to about 39°. Temperatures cover 56° across the year, low to high. By precipitation alone, it ranks drier than 91% of U.S. towns. The frost-free window for a garden runs roughly April 30 to October 26.
A year in Potrero at a glance
Each month’s typical high and low, and what it brings.
What stands out about Potrero’s climate
Compared with towns across the U.S., with Potrero’s place in California beside it.
What a year in Potrero feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 174 frost-free days a year
In half of years the last 32° night comes by April 30 and the first by October 26. Frost and day counts come from NOAA’s station at Campo, CA, 8 miles from the town’s center, 260 ft higher.
The 2023 USDA map puts Potrero’s center in zone 9a: the coldest night of a typical winter, averaged over 1991–2020, reaches about 24°. 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 17 inches of rain a year
February is the wettest month and June the driest. Rain falls on about 48 days a year. Snow is rare: about 0.3" in a normal year at Campo, CA, so most winters see none.
Rain + melted snow by month
Inches of water
Heating and cooling a home in Potrero
76% of the work is heating. Months averaging under 55° run from December through March.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Campo, CA.
Living with Potrero’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
174 frost-free days in zone 9a. The last frost comes by Apr 30 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 26.
Months with highs of 62–84° and lows of 40° or more: March, April, May, October and November. 2.1 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Potrero from natural hazards, wildfire is the largest share (91%). Normals are averages; the hazards page covers the extremes.
Natural hazards →Potrero and similar climates
TownRatings has no climate map of the towns around Potrero yet.
Climates most like Potrero’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 |
|---|---|---|---|---|
| Potrero, CA | 39° | 92° | 17" | 0.3" |
| Sierra Vista, AZ | 32° | 91° | 14" | 0.4" |
| Ashland, OR | 31° | 91° | 19" | 0.5" |
| Big Spring, TX | 33° | 95° | 18" | 2.0" |
| Santa Teresa, NM | 33° | 95° | 9" | 2.0" |
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 Potrero averaged 2.1° warmer than the 1900s. The biggest change is in January (+3.6°).
A bigger shift than in 92% 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 Potrero compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Potrero’s place among California’s.
Potrero weather by month
Highs, lows and precipitation from NOAA’s grid at Potrero’s center; snow, wet days and snow on the ground from Campo, CA. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 64° | 39° | 3.4" | 0.1" | 7 | 0 | 47° – 58° |
| February | 64° | 39° | 3.9" | 0.0" | 8 | 0 | 46° – 58° |
| March | 67° | 40° | 2.7" | 0.0" | 7 | 0 | 48° – 60° |
| April | 72° | 42° | 1.3" | 0.1" | 5 | 0 | 52° – 61° |
| May | 77° | 48° | 0.8" | 0.0" | 2 | 0 | 57° – 69° |
| June | 86° | 52° | 0.1" | 0.0" | 0 | 0 | 64° – 74° |
| July | 92° | 58° | 0.1" | 0.0" | 2 | 0 | 70° – 80° |
| August | 94° | 59° | 0.2" | 0.0" | 2 | 0 | 73° – 80° |
| September | 89° | 56° | 0.3" | 0.0" | 2 | 0 | 70° – 77° |
| October | 80° | 49° | 0.6" | 0.0" | 3 | 0 | 60° – 70° |
| November | 71° | 43° | 1.4" | 0.0" | 5 | 0 | 50° – 62° |
| December | 64° | 38° | 2.6" | 0.1" | 7 | 0 | 47° – 56° |
| Year | 77° | 47° | 17.4" | 0.3" | 48 | 0 |
How much a month can swing
A normal is an average. March swings the most: from 1991 to 2020 its average ranged from 48° to 60°. August is the most reliable, staying within 7°.
Where Potrero’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 Potrero’s center.
- Snow: Campo, CA.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Campo, CA, 8 miles from the town’s center, 260 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 Potrero’s climate
What is the weather like in Potrero?
A typical July afternoon reaches 92°, a January night drops to 39°, and snow is almost unheard of. Milder January nights than 88% of U.S. towns; hotter July afternoons than 88% of U.S. towns.
How cold does it get in Potrero in winter?
December nights average 38°. About 71 nights a year reach 32° or below. In the coldest December of the last 30 years the month averaged 47°.
How much snow does Potrero get?
About 0.3 inches in a normal winter at Campo, CA, so most winters see none.
How hot does it get in Potrero?
July, with a typical high of 92° and a low of 58°. About 97 days a year reach 90° and 18 reach 100° (Campo, CA).
When is the first and last frost in Potrero?
In half of years the last spring frost (32°) comes by April 30 and the first fall frost by October 26, about 174 frost-free days, at Campo, CA.
What growing zone is Potrero in?
Zone 9a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 24°.
What is the best time of year to visit Potrero?
By one simple rule (highs of 62–84° and lows of 40° or more), March, April, May, October and November. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Potrero getting warmer?
Yes: 1991–2020 averaged 2.1° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 92% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Potrero.
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.