Less rain and snow falls on McArthur than on 89% of U.S. towns: 22 inches a year
Midsummer highs settle at about 90°. December is the wettest month, August the driest. In July, afternoons here are warmer than in 78% of U.S. towns. Tender plants can go out after about May 29; in half of years the first frost comes by September 19.
A year in McArthur at a glance
Each month’s typical high and low, and what it brings.
What stands out about McArthur’s climate
Compared with towns across the U.S., with McArthur’s place in California beside it.
What a year in McArthur feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 113 frost-free days a year
In half of years the last 32° night comes by May 29 and the first by September 19. Frost and day counts come from NOAA’s station at Hat Creek, CA, 10 miles from the town’s center, 300 ft lower.
The 2023 USDA map puts McArthur’s center in zone 7a: the coldest night of a typical winter, averaged over 1991–2020, reaches about 5°. 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 Fall Rvr Mills, CA, falls mostly in February. Precipitation (rain plus melted snow) adds up to 22 inches a year; December is the wettest month and August the driest. Rain or snow falls on about 57 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in McArthur
94% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from October 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 Hat Creek, CA.
Living with McArthur’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
113 frost-free days in zone 7a. The last frost comes by May 29 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Sep 19.
Months with highs of 62–84° and lows of 40° or more: May, June and September. 1.8 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in McArthur from natural hazards, river flooding is the largest share (64%). Normals are averages; the hazards page covers the extremes.
Natural hazards →McArthur and similar climates
TownRatings has no climate map of the towns around McArthur yet.
Climates most like McArthur’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 |
|---|---|---|---|---|
| McArthur, CA | 26° | 90° | 22" | 3.0" |
| Milton-Freewater, OR | 30° | 90° | 17" | 7.2" |
| Littlefield, TX | 25° | 92° | 18" | 6.8" |
| College Place, WA | 30° | 91° | 15" | 7.2" |
| Prescott, AZ | 26° | 90° | 15" | 10" |
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 McArthur averaged 1.4° warmer than the 1900s. The biggest change is in January (+2.7°).
A bigger shift than in 52% 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 McArthur compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with McArthur’s place among California’s.
McArthur weather by month
Highs, lows and precipitation from NOAA’s grid at McArthur’s center; snow, wet days and snow on the ground from Fall Rvr Mills, CA. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 46° | 26° | 3.4" | 0.4" | 7 | 0 | 28° – 42° |
| February | 50° | 28° | 3.0" | 1.2" | 8 | 0 | 33° – 46° |
| March | 56° | 31° | 2.9" | 0.9" | 8 | 0 | 36° – 50° |
| April | 63° | 34° | 2.1" | 0.1" | 6 | 0 | 43° – 54° |
| May | 72° | 41° | 1.8" | 0.0" | 5 | 0 | 48° – 63° |
| June | 81° | 47° | 0.8" | 0.0" | 3 | 0 | 59° – 72° |
| July | 90° | 53° | 0.2" | 0.0" | 1 | 0 | 65° – 76° |
| August | 89° | 51° | 0.2" | 0.0" | 1 | 0 | 66° – 75° |
| September | 83° | 44° | 0.4" | 0.0" | 2 | 0 | 60° – 68° |
| October | 70° | 36° | 1.3" | 0.0" | 4 | 0 | 49° – 58° |
| November | 54° | 30° | 2.3" | 0.3" | 7 | 0 | 33° – 48° |
| December | 45° | 25° | 3.4" | 0.1" | 7 | 0 | 31° – 39° |
| Year | 66° | 37° | 21.8" | 3.0" | 57 | 1 |
How much a month can swing
A normal is an average. May swings the most: from 1991 to 2020 its average ranged from 48° to 63°. August is the most reliable, staying within 8°.
Where McArthur’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 McArthur’s center.
- Snow: Fall Rvr Mills, CA.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Hat Creek, CA, 10 miles from the town’s center, 300 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 McArthur’s climate
What is the weather like in McArthur?
A typical July afternoon reaches 90°, a January night drops to 26°, and about 3 inches of snow falls in a normal winter. Milder January nights than 66% of U.S. towns; hotter July afternoons than 78% of U.S. towns.
How cold does it get in McArthur in winter?
December nights average 25°. About 179 nights a year reach 32° or below. In the coldest December of the last 30 years the month averaged 31°.
How much snow does McArthur get?
About 3.0 inches in a normal winter at Fall Rvr Mills, CA, most of it in February, with snow on the ground about 1 days a year.
How hot does it get in McArthur?
July, with a typical high of 90° and a low of 53°. About 61 days a year reach 90° and 7 reach 100° (Hat Creek, CA).
When is the first and last frost in McArthur?
In half of years the last spring frost (32°) comes by May 29 and the first fall frost by September 19, about 113 frost-free days, at Hat Creek, CA.
What growing zone is McArthur in?
Zone 7a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 5°.
What is the best time of year to visit McArthur?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is McArthur getting warmer?
Yes: 1991–2020 averaged 1.4° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 52% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in McArthur.
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.