Photo: James Brooks · CC BY 2.0Hardly any U.S. towns see harsher January nights than McCarthy
July afternoons average 71°. Summers stay cool: July afternoons here are cooler than in almost every U.S. town. From frosty January to warm July, readings climb 81°. Plan time outside for July and August, when highs sit at 67–71°.
A year in McCarthy at a glance
Each month’s typical high and low, and what it brings.
What stands out about McCarthy’s climate
Compared with towns across the U.S., with McCarthy’s place in Alaska beside it.
What a year in McCarthy feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
A freeze is possible in every month
About 256 nights a year fall to 32° or below, and 91 to 0° or below. Frost and day counts come from Mccarthy 3 Sw, AK, 5 miles away.
The 2023 USDA map puts McCarthy’s center in zone 3a: the coldest night of a typical winter, averaged over 1991–2020, reaches about −35°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
About 67 inches of snow a winter
Snow, measured at Mccarthy 3 Sw, AK, falls mostly in January and November. Precipitation (rain plus melted snow) adds up to 18 inches a year; August is the wettest month and April the driest. Rain or snow falls on about 118 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in McCarthy
Nearly all of the work is heating: a normal year has almost no cooling days. Months averaging under 55°: every month but July.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Mccarthy 3 Sw, AK.
Living with McCarthy’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
Zone 3a, and frost can come in any month. The longest frost-free stretch in half of years is about 63 days.
Months with highs of 62–84° and lows of 40° or more: July and August. 39 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in McCarthy from natural hazards, avalanches are the largest share (76%); heat waves, cold waves, winter storms and ice storms together are 3%. Normals are averages; the hazards page covers the extremes.
Natural hazards →McCarthy and similar climates
TownRatings has no climate map of the towns around McCarthy yet.
Climates most like McCarthy’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 |
|---|---|---|---|---|
| McCarthy, AK | −9° | 71° | 18" | 67" |
| International Falls, MN | −5° | 78° | 28" | 73" |
| Superior, WI | 6° | 76° | 30" | 56" |
| Grand Forks, ND | −2° | 81° | 22" | 49" |
| Jackson, WY | 6° | 80° | 19" | 78" |
Temperatures and precipitation come from NOAA’s 5 km grid; snow and day counts from the stations named on this page.
How McCarthy compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with McCarthy’s place among Alaska’s.
McCarthy weather by month
Highs, lows and precipitation from the nearest NOAA station; snow, wet days and snow on the ground from Mccarthy 3 Sw, AK. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground |
|---|---|---|---|---|---|---|
| January | 6° | −9° | 0.9" | 13.2" | 9 | 31 |
| February | 21° | −1° | 1.1" | 7.9" | 7 | 28 |
| March | 33° | 4° | 0.4" | 5.4" | 5 | 31 |
| April | 48° | 22° | 0.3" | 2.5" | 3 | 28 |
| May | 62° | 31° | 0.9" | 0.6" | 7 | 3 |
| June | 70° | 39° | 1.6" | 0.0" | 11 | 0 |
| July | 71° | 43° | 2.5" | 0.0" | 14 | 0 |
| August | 67° | 40° | 2.7" | 0.0" | 16 | 0 |
| September | 56° | 33° | 2.6" | 2.7" | 15 | 1 |
| October | 39° | 20° | 2.2" | 9.4" | 11 | 13 |
| November | 17° | 2° | 1.5" | 13.5" | 10 | 29 |
| December | 9° | −5° | 1.1" | 11.3" | 9 | 31 |
| Year | 42° | 18° | 17.7" | 66.5" | 118 | 196 |
Where McCarthy’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s 1991–2020 normals at the nearest station (NOAA’s grid doesn’t cover Alaska).
- Snow: Mccarthy 3 Sw, AK.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Mccarthy 3 Sw, AK, 5 miles from the town’s center, 920 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.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about McCarthy’s climate
What is the weather like in McCarthy?
A typical July afternoon reaches 71°, a January night drops to −9°, and about 67 inches of snow falls in a normal winter. Colder January nights than all but 9 U.S. towns; cooler July afternoons than all but 103 U.S. towns.
How cold does it get in McCarthy in winter?
January nights average −9°. About 256 nights a year reach 32° or below and 91 reach 0° or below.
How much snow does McCarthy get?
About 67 inches in a normal winter at Mccarthy 3 Sw, AK, most of it in January and November, with snow on the ground about 196 days a year.
How hot does it get in McCarthy?
July, with a typical high of 71°. 90° days are rare: none in a normal year at Mccarthy 3 Sw, AK.
When is the first and last frost in McCarthy?
There is no reliable frost-free season: at Mccarthy 3 Sw, AK, every month has nights at 32° or below, about 256 a year. In half of years the longest stretch without a freeze is about 63 days.
What growing zone is McCarthy in?
Zone 3a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −35°.
What is the best time of year to visit McCarthy?
By one simple rule (highs of 62–84° and lows of 40° or more), July and August. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Neighbors talk weather
Gardens, snow, and the best days of the year in McCarthy.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.