Hummelstown, Pennsylvania Weather
Fireflies rise from the lawn. Day 77 of spring. Read this microseason across nine climate regions →
Hummelstown weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 4Overcast——87°54°—
- FridayJun 5Overcast——90°60°+3°
- SaturdayJun 6Overcast41%—83°61°-7°
- SundayJun 7Showers41%—85°64°+2°
- MondayJun 8Overcast——72°60°-13°
- TuesdayJun 9Overcast——80°54°+8°
- WednesdayJun 10Mostly Clear13%—85°58°+5°
PM2.5 at 11.5 µg/m³ (AQI 55) with a 0.97 fine-to-coarse ratio and 3 mph wind — combustion smoke trapped in calm air, not road dust. AQI down 17 over the last 6 hours — air quality is improving sharply.
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 11.5 µg/m³ (AQI 55) with a 0.97 fine-to-coarse ratio and 3 mph wind — combustion smoke trapped in calm air, not road dust.
- PM2.5/PM10
- 0.97
- Wind
- calm
- 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).
A summer fog for fair, a winter fog for rain.
- Moonrise
- 3:36 AM
- Moonset
- 1:06 PM
- In sign
- ♑︎ Capricorn
Fireflies rise from the lawn
Hummelstown at a glance
- Today vs. normal: 19°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 4, 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 — Hummelstown
SPC has placed Hummelstown in the General Thunderstorms category for severe thunderstorms day after tomorrow.
- TODAYNONENo severe risk
- TOMORROWNONENo severe risk
- DAY 3TSTMGeneral Thunderstorms
Thunderstorms possible. Not severe, but capable of producing lightning and brief heavy rain.
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.