Climate and average weather in Chambersburg

In Chambersburg, the summers are hot, showery, and partly cloudy and the winters are cold, snowy, and partly cloudy.

Best: early August to mid October

Over the course of the year, the temperature in Chambersburg typically varies from 23°F to 84°F, and is rarely below 8°F or above 92°F. July is the hottest month of the year, while January is the coldest.

Based on the travel score, the best times of year to visit Chambersburg for warm-weather activities are from late April to early July and early August to mid October.

Hottest
Jul
84°
Coldest
Jan
23°
Wettest
Sep
4.0 in
Driest
Feb
2.7 in
Rain / yr
40.8 in
116 wet days
Daylight
9.2–14.8 h
shortest–longest
Elevation
617 ft
39.9°N
Clearest
Oct
55% cloud

Chambersburg weather by month, at a glance

The whole year in one picture — sky, rain, humidity, temperature and travel score. Click any band to jump to its full chart.

Each stripe is one measure across the whole year, stacked so a single day reads top to bottom. The sky band runs overcast grey on top down to clear blue at the base — more blue means sunnier — followed by the rainfall curve, the humidity band, a temperature strip that tints each stretch of the year by how warm its average high is, and the travel-score line at the foot. Scan straight down any date to read that day across every measure at once; the score climbs highest around early August to mid October.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

Daily average highs and lows in Chambersburg, from 1991–2020 of climate data. The shaded bands show the range most days fall in — 10th to 90th percentile.

The hot season lasts 4.1 months, from May 23 to September 23, with daily high temperatures above 72°F. The hottest month of the year in Chambersburg is July, with an average high of 84°F and low of 66°F.

The cool season lasts 3.1 months, from December 1 to March 5, with daily high temperatures below 46°F. The coldest month of the year in Chambersburg is January, with an average low of 23°F and high of 37°F.

Days typically run about 17°F warmer than nights, with the widest day–night swing (around 19°F) in April.

20°40°60°80°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°F)Avg low (°F)
Jan3723
Feb4025
Mar4932
Apr6243
May7152
Jun8061
Jul8466
Aug8265
Sep7557
Oct6346
Nov5136
Dec4128

How hot and cold Chambersburg really feels

Feels-like highFeels-like lowactual air temp

The felt-temperature range through the year — heat index on the day's high (summer humidity), wind chill on the night's low (winter wind). The dashed lines are the plain thermometer; the gap is how much hotter or colder it really feels.

On the coldest nights, wind chill pulls the feels-like down to about 13°F (around January 24), with roughly 141 freezing days a year (feels-like at or below 32°F) 13 of them bitterly cold — worst in January.

20°40°60°80°JanFebMarAprMayJunJulAugSepOctNovDec
Feels-like high (°F)Air high (°F)Feels-like low (°F)Air low (°F)
Jan37371523
Feb40401725
Mar49492632
Apr62623943
May71715252
Jun80806161
Jul85846666
Aug83826565
Sep75755757
Oct63634346
Nov51513036
Dec41412128

Average hourly temperature in Chambersburg

A compact picture of the whole year, hour by hour: each column is a day, each row an hour, and the color is the modeled average temperature. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.

Read left to right for the day of the year and top to bottom for the hour of the day; the color is the modeled temperature, cool blues through to hot reds on the same scale as the other charts. A vertical slice is a single day's swing — coolest just before dawn, warmest in the mid-afternoon — while a horizontal slice follows one hour across the seasons. The darker overlay marks night and the lighter one the twilight around sunrise and sunset. Colors run warmest on July afternoons, near 84°F, and coldest before dawn in January, near 23°F.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM

Chambersburg weather by month

Every month at a glance. Click a month for its detailed page.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan37° / 23°3.194.39.50.0
Feb40° / 25°2.78.54.310.40.2
Mar49° / 32°3.810.53.211.72.1
Apr62° / 43°3.6110.4135.0
May71° / 52°3.812.4014.26.1
Jun80° / 61°3.510.8014.86.3
Jul84° / 66°3.510.1014.55.5
Aug82° / 65°2.89.1013.66.2
Sep75° / 57°4.09.3012.36.9
Oct63° / 46°3.38.20.210.95.8
Nov51° / 36°3.18.20.99.82.7
Dec41° / 28°3.38.62.79.20.2

Chance of rain

How likely it is to rain on a typical day, and how that shifts across the wetter and drier seasons.

Chambersburg gets about 40.8 in of precipitation a year. On a typical day the chance of rain is often wet, but that rises and falls sharply with the seasons.

The wetter season lasts 4.5 months, from around Feb 20 to Jul 7, peaking in May at about 42% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Nov 6.

September is the wettest month by volume, with 4.0 in over about 9 wet days; February is the driest, with 2.7 in. Some of the cold-season precipitation falls as snow.

0%10%20%30%40%50%JanFebMarAprMayJunJulAugSepOctNovDecdrierwetterdriermostly drysome rainoften wetvery wetMay 7 · 42%Nov 6 · 25%
Rain on a day (%)Rain days
Jan299
Feb309
Mar3411
Apr3711
May4012
Jun3611
Jul3210
Aug309
Sep299
Oct278
Nov288
Dec299

Monthly rainfall

Over a full year, Chambersburg collects about 40.8 in of rain across 116 wet days — roughly 3.4 in in an average month.

It doesn’t fall evenly. September is the wettest month with 4.0 in, while February is the driest at just 2.7 in. The three wettest months alone bring about 28% of the year’s total, and some of the cold-season precipitation falls as snow.

012345JanFebMarAprMayJunJulAugSepOctNovDec3.12.73.83.63.83.53.52.84.03.33.13.3
Rainfall (in)Rain daysSnow days
Jan3.194
Feb2.794
Mar3.8113
Apr3.6110
May3.8120
Jun3.5110
Jul3.5100
Aug2.890
Sep4.090
Oct3.380
Nov3.181
Dec3.393

Snow in Chambersburg

Average snowy days through the year, the snow-season span, and estimated snowfall — for ski trips and the perennial 'will there be snow at Christmas?' question.

Chambersburg averages about 16 snowy days a year. Snow season runs roughly Nov 7 to Apr 11 — about 5.1 months.

February is snowiest, with roughly 5 days of snow and an estimated 14 in of snowfall. Over the year that adds up to an estimated 48 in of snow.

02468JanFebMarAprMayJunJulAugSepOctNovDecsnow seasonsnow seasonFeb 6
Snow daysSnowfall (in)
Jan410
Feb414
Mar311
Apr01
May00
Jun00
Jul00
Aug00
Sep00
Oct00
Nov13
Dec39

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

How often the daytime sky is clear, partly cloudy or overcast.

In Chambersburg, the average share of the sky covered by clouds shows moderate seasonal variation over the course of the year.

The clearer part of the year begins around June 1 and lasts for 5.6 months, ending around November 17. The clearest month is September, when the sky is clear, mostly clear, or partly cloudy 52% of the time on average.

The cloudier part of the year begins around November 18 and lasts for 6.4 months, ending around May 31. The cloudiest month is January, when it is overcast or mostly cloudy 65% of the time.

0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%JanFebMarAprMayJunJulAugSepOctNovDecOct 4 · 54%Dec 10 · 33%clearmostly clearpartly cloudymostly cloudyovercastcloudierclearercloudier
Clearer (%)Cloudier (%)
Jan3565
Feb3862
Mar3763
Apr3763
May4060
Jun4654
Jul5050
Aug5149
Sep5248
Oct5248
Nov4456
Dec3565

Daylight, sunrise and sunset

DaylightNight

Hours of daylight through the year, with sunrise and sunset times.

The gold band is daylight — sunrise runs along its lower edge, sunset along the upper — so it widens toward summer and pinches toward winter, with night the dark area above and below. The longest day, around June 10, brings about 14 h 48 min of light; the shortest, around January 1, only 9 h 12 min — a swing of roughly 5 h 36 min.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan9.57:365:04
Feb10.47:125:38
Mar11.76:306:11
Apr13.05:396:42
May14.25:017:13
Jun14.84:467:35
Jul14.54:597:33
Aug13.65:277:02
Sep12.35:576:13
Oct10.96:285:23
Nov9.87:034:49
Dec9.27:314:42

Sunny days

How many genuinely sunny days each month brings — days the sky stays clear or mostly clear — banded into plain-language zones.

Chambersburg averages about 8 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 6 and 11 days.

The sunnier stretch runs 3.8 months, from around Jul 27 to Nov 20. The sunniest month is October, with roughly 11 sunny days (mixed).

The greyest month is January, down near 6 sunny days — about 44% fewer than the October peak.

051015JanFebMarAprMayJunJulAugSepOctNovDecgreyersunniergreyergloomymixedOct 411 daysJan 166 days
Sunny daysSky
Jan6Gloomy
Feb6Gloomy
Mar7Gloomy
Apr7Gloomy
May7Gloomy
Jun7Gloomy
Jul9Mixed
Aug9Mixed
Sep11Mixed
Oct11Mixed
Nov9Mixed
Dec7Gloomy

Humidity comfort

DryComfortableHumidMuggyOppressiveMiserable

Share of days at each humidity comfort level, based on the dew point — the measure that tracks how muggy it actually feels.

Humidity comfort is graded by the dew point — the temperature at which the air would be fully saturated — because it tracks how muggy it actually feels far better than relative humidity does. A low dew point feels dry and crisp; a high one feels sticky and oppressive no matter the reading on a humidity gauge.

In Chambersburg, how humid it feels changes dramatically over the year.

The more humid part of the year lasts 4.3 months, from around May 21 to September 28. The muggiest month is July, when the air feels humid, muggy or worse about 67% of the time.

The most comfortable stretch runs from around September 29 to May 20, and January is the most comfortable month — the air is dry or comfortable 100% of the time.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecJan 1 · 100%Jul 22 · 29%muggydryhumidcomfortablecomfortablehumidcomfortable
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
Jan1000000
Feb1000000
Mar1000000
Apr945100
May67171240
Jun302322222
Jul132027337
Aug182326285
Sep472217121
Oct8410420
Nov972000
Dec1000000

Wind

Average wind speed through the year, banded into plain-language speed zones so a number reads as 'breezy' or 'calm' without knowing the scale.

This is the average sustained wind speed at the standard 10 metres above open ground — the steady flow a weather station reports, not the sharper gusts that come and go, which can run half again as fast. It's the number that says whether a place is generally breezy or calm.

Across the year, average wind speed in Chambersburg is typically calm, near 6 mph, and varies little with the seasons.

The windier part of the year lasts 6.7 months, from around Oct 17 to May 8. The windiest month is March, averaging about 7 mph (calm).

The calmer part of the year runs from around May 9 to Oct 16, with August the calmest month at about 5 mph.

0510JanFebMarAprMayJunJulAugSepOctNovDecwindiercalmerwindiercalmlight breezeMar 4 · 7 mphAug 7 · 5 mph
Wind speed (mph)Feels
Jan7calm
Feb7calm
Mar7calm
Apr7calm
May6calm
Jun5calm
Jul5calm
Aug5calm
Sep5calm
Oct6calm
Nov7calm
Dec7calm

Best time to visit Chambersburg

TravelBeach/poolTemperatureCloudsPrecipitation

To characterize how pleasant the weather is in Chambersburg throughout the year, we compute two travel scores — one for general sightseeing, one for beach and pool weather.

Around mid August, Chambersburg is still near the start of its best-weather window — great conditions with the peak-season crowds not yet at full swing.

Inferred from the travel-score curve; month-by-month visitor numbers are a planned addition.

The travel score favors clear, rainless days with daytime highs between 64°F and 82°F. Based on this score, the best times of year to visit Chambersburg for general outdoor tourist activities run from late April to early July and again from early August to mid October, with a peak score in the third week of September.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timebest timetravel scoretemperaturecloudsprecipitationSep 15 · 7.1

The travel score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

Travel score (0–10)Rating
Jan0.0poor
Feb0.2poor
Mar2.1poor
Apr5.0fair
May6.1good
Jun6.3good
Jul5.6good
Aug6.2good
Sep6.9good
Oct5.8good
Nov2.7poor
Dec0.3poor

The beach/pool score favors clear, rainless days with daytime highs between 75°F and 93°F. Based on this score, the best time of year to visit Chambersburg for hot-weather activities is from early June to mid September, with a peak score in the second week of July.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebeach/pool scoretemperaturecloudsprecipitationJul 14 · 7.1

The beach/pool score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

What to pack for Chambersburg, by month

EssentialRecommendedOptional

Month by month, what's worth putting in the bag — from the temperature range, rain chance, sun and wind. Tap a month for a quick packing note.

For a warm-season trip around July (highs near 84°F), the essentials are light clothes, rain gear and sun protection. In the cold season around January (highs near 37°F), pack a warm layer, a heavy coat and rain gear.

Light clothing
Warm layer
Winter coat
Rain gear
Sun protection
Windbreaker

In July, Chambersburg sees daytime highs around 84°F and nights near 66°F. Pack light clothes and sun protection. Worth having: rain gear. About 10 days see rain.

UV index (midday) in Chambersburg by month

LowModerateHighVery highExtreme

Clear-sky midday UV index through the year, shaded by the WHO exposure levels — how much sun protection each month calls for.

Under clear skies, the midday UV index in Chambersburg peaks around June 22 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near December 20 at about 2 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 9 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecModerateHighVery highHighModerateLowJun 22UV 9Dec 20UV 2
UV index (midday)Level
Jan2Low
Feb3Moderate
Mar5Moderate
Apr6High
May8Very high
Jun9Very high
Jul9Very high
Aug7High
Sep6High
Oct3Moderate
Nov2Moderate
Dec2Low

Average hourly UV index in Chambersburg

LowModerateHighVery highExtreme

Modeled clear-sky UV for every hour of every day — when in the day sun protection actually matters.

The whole year hour by hour: each column is a day, each row an hour, and the color is the modeled clear-sky UV index — the midday peak scaled down as the sun sits lower in the sky. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.

UV falls off far faster than brightness as the sun drops, so even in June the burn window is concentrated in the middle of the day: about 8.5 hours a day reach index 3 (protection recommended), and 5 hours reach 6 or more. Mornings and late afternoons stay comparatively gentle year round.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM
UV ≥ 3 (h/day)UV ≥ 6 (h/day)
Jan00
Feb10
Mar50
Apr6.51.5
May7.54
Jun8.55
Jul85
Aug73
Sep61
Oct2.50
Nov00
Dec00

Air quality in Chambersburg by month

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see which months the air is worst, not just the yearly average.

Air quality in Chambersburg is worst in July — around 16 µg/m³ PM2.5 (moderate), about 2.2× the cleanest month (November, 7 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1316 µg/m³Nov 137 µg/m³
PM2.5 (µg/m³)Level
Jan9Good
Feb11Good
Mar12Good
Apr12Good
May14Moderate
Jun16Moderate
Jul16Moderate
Aug14Moderate
Sep11Good
Oct8Good
Nov7Good
Dec8Good
Almanac & agriculture

Growing season

Chance of a frost-free dayTypical season (≥50%)

The growing season in Chambersburg typically lasts about 260 days, from around March 17 to December 1 — the span where a frost-free day is more likely than not. It is reliably frost-free from April 15 to October 26.

0%25%50%75%100%JanFebMarAprMayJunJulAugSepOctNovDecgrowing seasonMar 1750%Apr 1590%Oct 2690%Dec 150%
Frost-free chance (%)Frost nights
Jan2131
Feb2428
Mar5231
Apr9011
May1000
Jun1000
Jul1000
Aug1000
Sep1000
Oct953
Nov6730
Dec3431

Growing degree days

Degree days (base 50°F)Frost-free shaded

Growing degree days tally heat above 50°F: each day adds however many degrees its average temperature runs over that threshold, and cold days add nothing. Chambersburg banks about 3,183 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around July.

01,0002,0003,000JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°F·days)
Jan0
Feb0
Mar0
Apr83
May357
Jun615
Jul774
Aug725
Sep488
Oct142
Nov0
Dec0

Solar energy

Average daily shortwave solar energy reaching the ground, banded into brightness zones so the number means something at a glance.

Solar energy is how much sunlight actually reaches the ground each day, measured in kilowatt-hours per square metre (kWh/m²) — the combined effect of how long the sun is up, how high it climbs, and how much cloud gets in the way. It's the raw fuel a solar panel has to work with: for scale, 1 kWh/m² a day is dim and wintry, while 7+ is desert-bright.

Chambersburg receives about 4.0 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 1.7 and 6.2 kWh/m².

The brighter stretch of the year lasts 6.2 months, from around Mar 17 to Sep 20. The brightest month is July, averaging about 6.0 kWh/m² (intense).

The dimmest month is December, down near 1.8 kWh/m² — roughly 71% less than the July peak.

01234567JanFebMarAprMayJunJulAugSepOctNovDecdimmerbrighterdimmerdimmoderatebrightintenseJul 36.2 kWhDec 151.7 kWh
Solar energy (kWh/m²)Level
Jan2.1Moderate
Feb3.0Moderate
Mar4.0Bright
Apr5.0Bright
May5.6Bright
Jun6.1Intense
Jul6.0Intense
Aug5.3Bright
Sep4.2Bright
Oct3.2Moderate
Nov2.2Moderate
Dec1.8Dim

Where is Chambersburg?

Chambersburg sits at 39.9°N, 77.7°W, 617 ft above sea level, in United States. The nearest listed city is Hagerstown, 21 mi away.

Topography around Chambersburg

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Chambersburg.

Within 2 miles, the terrain around Chambersburg has only modest variations in elevation — a maximum elevation change of 220 ft around an average of 659 ft above sea level; within 10 miles, significant variations in elevation — a maximum elevation change of 1,877 ft; within 50 miles, large variations in elevation — a maximum elevation change of 2,802 ft.

The land around Chambersburg is covered by trees (30%), artificial surfaces (29%) and grassland (26%) within 2 miles, trees (40%), cropland (34%) and grassland (21%) within 10 miles, and trees (64%) within 50 miles.

2 miles
220 ft
10 miles
1,877 ft
50 miles
2,802 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
Nearby: Hagerstown 21 mi · Carlisle 31 mi · Martinsburg 37 mi · Hanover 37 mi · Frederick 39 mi · Ballenger Creek 41 mi · Westminster 43 mi · Harrisburg 47 mi

United States travel facts

Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 100% of US
price level, 2025
GDP per capita
$90,027
2025
Happiness
6.8 / 10
World Happiness, 2025
Safe drinking water
98%
of population, 2024
Homicide rate
5.8
per 100k, 2023
Road deaths
12.7
per 100k/yr, 2019
Income group
High
World Bank
Religion
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Chambersburg (39.9376°, -77.6611°, elevation 617 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).