Derry, PA
Full City Profile · Pennsylvania · Westmoreland County County
2.7
/5.0
C+
Fair
2,616
Population
3,397/sq mi density
$49,051
Median Income
$29,908 per capita
$122,200
Home Value
$205,937 Zillow
$593
Median Rent
30.6% income on rent
50°F
Avg Temperature
117
Violent Crime/100K
272 property/100K
C+
Overall
2.7 / 5.0
Fair overall score based on economy, affordability, safety and education
C+
Economy
2.5 / 5.0
$49,051 median income, 9.7% unemployment
A+
Affordability
5.0 / 5.0
$122,200 home value, $593/mo rent
F
Safety
1.0 / 5.0
117 violent crimes/100K
C
Education
2.3 / 5.0
16.1% bachelor's degree or higher
Derry experiences four distinct seasons with an average annual temperature of 50°F (10°C). Winters average 27°F in January while summers reach 70°F in July. Annual precipitation totals 49.6 inches. The area receives 48.2 inches of snow annually. Air quality is rated Good with a median AQI of 39.
Temperature
27°F Jan (-3°C)
70°F Jul (21°C)
| Annual Average | 49.6°F |
| 8% below US avg | |
| January Average | 27°F (-3°C) |
| July Average | 70°F (21°C) |
Geography
| Elevation | 1,179 ft (359 m) |
| Area | 0.3 sq mi (0.8 km²) |
| Population Density | 3,397/sq mi |
| Coordinates | 40.3334°N, 79.3011°W |
| Timezone | America/New_York |
| County | Westmoreland County County |
| Nearest Airport | Arnold Palmer Regional (LBE) 7 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 39.0 |
| Rating | Good |
| Good Days % | 76.6% |
| Unhealthy Days | 0 |
Air Pollutants (EPA 2023)
| Ozone (O₃) | 0.0423 ppm |
| PM2.5 (Fine Particles) | 8.3 μg/m³ |
Natural Hazard Risk
| Overall Risk | Relatively Moderate |
| Risk Score | 87.9 / 100 |
| Social Vulnerability | 30.2 / 100 |
| Community Resilience | 92.8 / 100 |
Hazard Breakdown
| Tornado | Relatively Low |
| Hurricane | Relatively Low |
| Earthquake | Relatively Low |
| Wildfire | Very Low |
| Flood | Relatively High |
| Hail | Relatively Moderate |
| Strong Wind | Relatively High |
| Heat Wave | Relatively Low |
| Winter Weather | Relatively Moderate |
| Lightning | Relatively High |
| Ice Storm | Relatively Moderate |
| Drought | Very Low |
| Cold Wave | Very Low |
| Landslide | Relatively Moderate |
| Avalanche | Very Low |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 27°F (-3°C) | 3.8 in | Coldest |
| February | 30°F (-1°C) | 3.2 in | |
| March | 38°F (3°C) | 4.2 in | |
| April | 50°F (10°C) | 4.3 in | |
| May | 59°F (15°C) | 4.9 in | Wettest |
| June | 66°F (19°C) | 4.7 in | |
| July | 70°F (21°C) | 4.7 in | Warmest |
| August | 69°F (20°C) | 4.8 in | |
| September | 62°F (16°C) | 4.1 in | |
| October | 52°F (11°C) | 3.2 in | Driest |
| November | 42°F (5°C) | 4.1 in | |
| December | 33°F (1°C) | 3.7 in |
Derry has a seasonal temperature swing of 43°F / from 27°F in January to 70°F in July. Total annual precipitation is 49.6 inches, with May being the wettest month (4.9") and October the driest (3.2").