Photo: Father of Nehrams2020 · CC BY-SA 3.0Atwater reaches 100° on about 25 days a year, more than 97% of U.S. towns
A typical July afternoon reaches 95°, a January night drops to 39°, and snow is almost unheard of.
A year in Atwater at a glance
Each month’s typical high and low, and what it brings.
What stands out about Atwater’s climate
Compared with towns across the U.S., with Atwater’s place in California beside it.
What a year in Atwater feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 263 frost-free days a year
In half of years the last 32° night comes by March 3 and the first by November 24. Frost and day counts come from NOAA’s station at Merced, CA, 6 miles from the town’s center, at about the same height.
The 2023 USDA map puts Atwater’s center in zone 9b: the coldest night of a typical winter, averaged over 1991–2020, reaches about 25°. 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 12 inches of rain a year
January is the wettest month and July the driest. Rain falls on about 52 days a year. Snow is rare: about 0.0" in a normal year at Merced, CA, so most winters see none.
Rain + melted snow by month
Inches of water
Heating and cooling a home in Atwater
65% of the work is heating. Months averaging under 55° run from November through February.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Merced, CA.
Living with Atwater’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
263 frost-free days in zone 9b. The last frost comes by Mar 3 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 24.
Months with highs of 62–84° and lows of 40° or more: March, April, May, October and November. 7.6 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Atwater from natural hazards, river flooding is the largest share (55%); heat waves, cold waves, winter storms and ice storms together are 9%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Atwater and similar climates
TownRatings has no climate map of the towns around Atwater yet.
Climates most like Atwater’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 |
|---|---|---|---|---|
| Atwater, CA | 39° | 95° | 12" | 0.0" |
| Corona de Tucson, AZ | 36° | 96° | 14" | 0.1" |
| Fort Stockton, TX | 33° | 96° | 13" | 1.4" |
| Anthony, NM | 31° | 96° | 9" | 0.0" |
| Ivins, UT | 32° | 100° | 11" | 1.2" |
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 Atwater averaged 1.5° warmer than the 1900s. The biggest change is in January (+2.2°).
A bigger shift than in 60% 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 Atwater compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Atwater’s place among California’s.
Atwater weather by month
Highs, lows and precipitation from NOAA’s grid at Atwater’s center; snow, wet days and snow on the ground from Merced, CA. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 56° | 39° | 2.6" | 0.0" | 10 | 0 | 43° – 51° |
| February | 62° | 41° | 2.2" | 0.0" | 9 | 0 | 48° – 55° |
| March | 68° | 44° | 1.9" | 0.0" | 8 | 0 | 50° – 61° |
| April | 74° | 47° | 1.0" | 0.0" | 4 | 0 | 56° – 65° |
| May | 82° | 53° | 0.5" | 0.0" | 3 | 0 | 60° – 74° |
| June | 90° | 59° | 0.1" | 0.0" | 1 | 0 | 70° – 78° |
| July | 95° | 63° | 0.0" | 0.0" | 0 | 0 | 76° – 84° |
| August | 94° | 62° | 0.0" | 0.0" | 0 | 0 | 74° – 81° |
| September | 90° | 58° | 0.1" | 0.0" | 1 | 0 | 71° – 77° |
| October | 79° | 51° | 0.6" | 0.0" | 3 | 0 | 62° – 69° |
| November | 66° | 43° | 1.1" | 0.0" | 5 | 0 | 48° – 59° |
| December | 56° | 38° | 2.1" | 0.0" | 9 | 0 | 43° – 52° |
| Year | 76° | 50° | 12.1" | 0.0" | 52 | 0 |
How much a month can swing
A normal is an average. May swings the most: from 1991 to 2020 its average ranged from 60° to 74°. September is the most reliable, staying within 6°.
Where Atwater’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 Atwater’s center.
- Snow: Merced, CA.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Merced, CA, 6 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 Atwater’s climate
What is the weather like in Atwater?
A typical July afternoon reaches 95°, a January night drops to 39°, and snow is almost unheard of. Milder January nights than 86% of U.S. towns; hotter July afternoons than 95% of U.S. towns.
How cold does it get in Atwater in winter?
December nights average 38°. About 24 nights a year reach 32° or below. In the coldest December of the last 30 years the month averaged 43°.
How much snow does Atwater get?
About 0.0 inches in a normal winter at Merced, CA, so most winters see none.
How hot does it get in Atwater?
July, with a typical high of 95° and a low of 63°. About 106 days a year reach 90° and 25 reach 100° (Merced, CA).
When is the first and last frost in Atwater?
In half of years the last spring frost (32°) comes by March 3 and the first fall frost by November 24, about 263 frost-free days, at Merced, CA.
What growing zone is Atwater in?
Zone 9b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 25°.
What is the best time of year to visit Atwater?
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 Atwater getting warmer?
Yes: 1991–2020 averaged 1.5° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 60% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Atwater.
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.