Harleysville, Pennsylvania Weather
Fireflies rise from the lawn. Day 78 of spring. Read this microseason across nine climate regions →
Harleysville weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 5Overcast——91°58°—
- SaturdayJun 6Overcast31%—91°63°0°
- SundayJun 7Light Drizzle31%—84°65°-7°
- MondayJun 8Overcast——81°55°-3°
- TuesdayJun 9Overcast——78°53°-3°
- WednesdayJun 10Overcast15%—84°61°+6°
- ThursdayJun 11Light Drizzle23%—79°65°-5°
AQI 42 (Good), driven by PM2.5. AQI down 9 over the last 6 hours (steady decline since this morning). PM2.5 at 12.9 µg/m³ (AQI 58) with a 0.99 fine-to-coarse ratio and 6 mph wind — combustion smoke trapped in calm air, not road dust.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion.
What's driving it
PM × Wind × Precip
PM2.5 at 12.9 µg/m³ (AQI 58) with a 0.99 fine-to-coarse ratio and 6 mph wind — combustion smoke trapped in calm air, not road dust.
- PM2.5/PM10
- 0.99
- Wind
- light
- Recent rain
- 0h in last 6h
- Pattern
- stagnant smoke
Trends
Seven days of AQI and PM2.5.
Hourly air-quality data from the Copernicus Atmosphere Monitoring Service, charted across the past and next several days. Dashed lines mark the AQI breakpoints at 50 (Good → Moderate) and 100 (Moderate → Unhealthy for Sensitive Groups).
The higher the clouds, the finer the weather.
- Moonrise
- 4:01 AM
- Moonset
- 2:05 PM
- In sign
- ♒︎ Aquarius
Fireflies rise from the lawn
Harleysville at a glance
- Today vs. normal: 17°F below the seasonal normal for this latitude
- Last frost: April 18 (climatological average for this latitude)
- Microseason: Jun 1–5
- Planting window: Harvest spring lettuce before it bolts. Sow heat-tolerant greens.
Right now in the garden
Peak growing season
As of June 5, the growing season is at its peak — frost is months away. Continue succession-planting beans and summer squash. Start fall brassicas (broccoli, cabbage, kale) from seed indoors for transplanting in late summer.
SPC Convective Outlook
Storm Prediction Center — Harleysville
SPC has placed Harleysville in the Marginal Risk category for severe thunderstorms tomorrow.
- TODAYNONENo severe risk
- TOMORROWMRGLMarginal Risk
- DAY 3TSTMGeneral Thunderstorms
Isolated severe storms possible. Limited threat for hail or damaging wind.
Source: NOAA / NWS Storm Prediction Center categorical convective outlook. Outlooks are re-issued multiple times per day; this page reflects the most recent SPC polygons covering the city’s coordinates.