Photo: Lee Paxton · CC BY-SA 4.0Carnegie’s winters are milder but snowier than most of the U.S.
A typical July afternoon reaches 84°, a January night drops to 22°, and about 44 inches of snow falls in a normal winter.
A year in Carnegie at a glance
Each month’s typical high and low, and what it brings.
What stands out about Carnegie’s climate
Compared with towns across the U.S., with Carnegie’s place in Pennsylvania beside it.
What a year in Carnegie feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 181 frost-free days a year
In half of years the last 32° night comes by April 23 and the first by October 23. Frost and day counts come from NOAA’s station at Pittsburgh International Airport, 9 miles from the town’s center, 360 ft higher.
The 2023 USDA map puts Carnegie’s center in zone 7a: the coldest night of a typical winter, averaged over 1991–2020, reaches about 0°. 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 44 inches of snow a winter
Snow, measured at Pittsburgh International Airport, falls mostly in January. Precipitation (rain plus melted snow) adds up to 40 inches a year; July is the wettest month and February the driest. Rain or snow falls on about 154 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Carnegie
87% 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 Pittsburgh International Airport.
Living with Carnegie’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
181 frost-free days in zone 7a. The last frost comes by Apr 23 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 23.
Months with highs of 62–84° and lows of 40° or more: April, May, June, August, September and October. 0.5 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Carnegie from natural hazards, river flooding is the largest share (85%); heat waves, cold waves, winter storms and ice storms together are 11%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Carnegie and its neighbors
Every town next door is within a degree of Carnegie in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Carnegie’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 |
|---|---|---|---|---|
| Carnegie, PA | 22° | 84° | 40" | 44" |
| East Chicago, IN | 19° | 83° | 38" | 39" |
| Chicago, IL | 18° | 84° | 38" | 39" |
| Bellevue, OH | 19° | 84° | 38" | 33" |
| Three Rivers, MI | 17° | 83° | 38" | 41" |
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value. Snow and frost-free days come from the nearest weather station, so neighbors often share them.
Warmer than it used to be
The last 30 years in Carnegie averaged 1.2° warmer than the 1900s. The biggest change is in December (+2.5°).
A smaller 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 Carnegie compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Carnegie’s place among Pennsylvania’s.
Carnegie weather by month
Highs, lows and precipitation from NOAA’s grid at Carnegie’s center; snow, wet days and snow on the ground from Pittsburgh International Airport. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 38° | 22° | 2.9" | 13.3" | 17 | 14 | 22° – 39° |
| February | 41° | 24° | 2.5" | 11.7" | 14 | 11 | 20° – 41° |
| March | 51° | 31° | 3.2" | 7.6" | 14 | 5 | 34° – 52° |
| April | 64° | 40° | 3.4" | 1.0" | 14 | 0 | 46° – 57° |
| May | 73° | 50° | 3.9" | 0.0" | 14 | 0 | 55° – 68° |
| June | 81° | 59° | 4.1" | 0.0" | 12 | 0 | 66° – 72° |
| July | 84° | 63° | 4.3" | 0.0" | 11 | 0 | 70° – 78° |
| August | 83° | 62° | 3.6" | 0.0" | 11 | 0 | 68° – 77° |
| September | 77° | 55° | 3.4" | 0.0" | 10 | 0 | 62° – 70° |
| October | 65° | 44° | 2.9" | 0.4" | 11 | 0 | 50° – 60° |
| November | 53° | 34° | 2.8" | 2.4" | 12 | 1 | 37° – 49° |
| December | 42° | 27° | 3.0" | 7.7" | 15 | 8 | 24° – 45° |
| Year | 63° | 42° | 40.0" | 44.1" | 154 | 40 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 20° to 41°. June is the most reliable, staying within 7°.
Where Carnegie’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 Carnegie’s center.
- Snow: Pittsburgh International Airport.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Pittsburgh International Airport, 9 miles from the town’s center, 360 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 Carnegie’s climate
What is the weather like in Carnegie?
A typical July afternoon reaches 84°, a January night drops to 22°, and about 44 inches of snow falls in a normal winter. Milder January nights than 50% of U.S. towns; cooler July afternoons than 57% of U.S. towns.
How cold does it get in Carnegie in winter?
January nights average 22°. About 114 nights a year reach 32° or below and 2 reach 0° or below. In the coldest January of the last 30 years the month averaged 22°.
How much snow does Carnegie get?
About 44 inches in a normal winter at Pittsburgh International Airport, most of it in January, with snow on the ground about 40 days a year.
How hot does it get in Carnegie?
July, with a typical high of 84° and a low of 63°. About 10 days a year reach 90° (Pittsburgh International Airport).
When is the first and last frost in Carnegie?
In half of years the last spring frost (32°) comes by April 23 and the first fall frost by October 23, about 181 frost-free days, at Pittsburgh International Airport.
What growing zone is Carnegie in?
Zone 7a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 0°.
What is the best time of year to visit Carnegie?
By one simple rule (highs of 62–84° and lows of 40° or more), April, May, June, August, September and October. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Carnegie getting warmer?
Yes: 1991–2020 averaged 1.2° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 60% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Carnegie.
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.