Photo: Nyttend · Public domainSummers in Knox are cooler than in 82% of U.S. towns
In January the night’s low is typically 18°. Winter nights are cold: in January they are colder than in 72% of U.S. towns. Warming shows here too: 1.6° more than in 1901–2000, led by December. The heating season runs November to April: each of those months averages under 50°.
A year in Knox at a glance
Each month’s typical high and low, and what it brings.
What stands out about Knox’s climate
Compared with towns across the U.S., with Knox’s place in Pennsylvania beside it.
What a year in Knox feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 154 frost-free days a year
In half of years the last 32° night comes by May 9 and the first by October 11. Frost and day counts come from NOAA’s station at Clarion 3 Sw, PA, 6 miles from the town’s center, 320 ft lower.
The 2023 USDA map puts Knox’s center in zone 6a: the coldest night of a typical winter, averaged over 1991–2020, reaches about −7°. 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 54 inches of snow a winter
Snow, measured at Franklin, PA, falls mostly in January. Precipitation (rain plus melted snow) adds up to 46 inches a year; June is the wettest month and February the driest. Rain or snow falls on about 170 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Knox
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 Clarion 3 Sw, PA.
Living with Knox’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
154 frost-free days in zone 6a. The last frost comes by May 9 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 11.
Months with highs of 62–84° and lows of 40° or more: May, June, July, August and September. 0.0 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Knox from natural hazards, river flooding is the largest share (58%); heat waves, cold waves, winter storms and ice storms together are 10%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Knox and similar climates
TownRatings has no climate map of the towns around Knox yet.
Climates most like Knox’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 |
|---|---|---|---|---|
| Knox, PA | 18° | 82° | 46" | 54" |
| Groveland, MA | 17° | 82° | 47" | 58" |
| Plattekill, NY | 17° | 83° | 45" | 59" |
| Ellington, CT | 18° | 83° | 48" | 52" |
| Exeter, NH | 16° | 82° | 47" | 57" |
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 Knox averaged 1.6° warmer than the 1900s. The biggest change is in December (+2.7°).
A bigger shift than in 66% 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 Knox compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Knox’s place among Pennsylvania’s.
Knox weather by month
Highs, lows and precipitation from NOAA’s grid at Knox’s center; snow, wet days and snow on the ground from Franklin, PA. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 34° | 18° | 3.5" | 17.9" | 18 | 19 | 18° – 35° |
| February | 37° | 19° | 2.6" | 11.5" | 15 | 16 | 13° – 37° |
| March | 46° | 26° | 3.5" | 8.9" | 14 | 8 | 30° – 48° |
| April | 60° | 36° | 4.0" | 1.1" | 14 | 1 | 42° – 53° |
| May | 71° | 45° | 3.9" | 0.0" | 15 | 0 | 50° – 65° |
| June | 78° | 54° | 5.0" | 0.0" | 14 | 0 | 62° – 69° |
| July | 82° | 59° | 4.8" | 0.0" | 12 | 0 | 66° – 74° |
| August | 80° | 57° | 3.9" | 0.0" | 12 | 0 | 65° – 73° |
| September | 74° | 51° | 3.9" | 0.0" | 11 | 0 | 59° – 67° |
| October | 62° | 40° | 3.7" | 0.0" | 15 | 0 | 47° – 57° |
| November | 49° | 31° | 3.5" | 2.6" | 14 | 2 | 35° – 46° |
| December | 38° | 24° | 3.5" | 11.7" | 17 | 10 | 21° – 42° |
| Year | 59° | 38° | 45.6" | 53.7" | 170 | 56 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 13° to 37°. June is the most reliable, staying within 7°.
Where Knox’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 Knox’s center.
- Snow: Franklin, PA.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Clarion 3 Sw, PA, 6 miles from the town’s center, 320 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 Knox’s climate
What is the weather like in Knox?
A typical July afternoon reaches 82°, a January night drops to 18°, and about 54 inches of snow falls in a normal winter. Colder January nights than 72% of U.S. towns; cooler July afternoons than 82% of U.S. towns.
How cold does it get in Knox in winter?
January nights average 18°. About 155 nights a year reach 32° or below and 8 reach 0° or below. In the coldest January of the last 30 years the month averaged 18°.
How much snow does Knox get?
About 54 inches in a normal winter at Franklin, PA, most of it in January, with snow on the ground about 56 days a year.
How hot does it get in Knox?
July, with a typical high of 82° and a low of 59°. About 9 days a year reach 90° (Clarion 3 Sw, PA).
When is the first and last frost in Knox?
In half of years the last spring frost (32°) comes by May 9 and the first fall frost by October 11, about 154 frost-free days, at Clarion 3 Sw, PA.
What growing zone is Knox in?
Zone 6a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −7°.
What is the best time of year to visit Knox?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June, July, August and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Knox getting warmer?
Yes: 1991–2020 averaged 1.6° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 66% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Knox.
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.