Mount Gretna, Pennsylvania Weather
Cicadas claim the afternoon. Day 14 of summer. Read this microseason across nine climate regions →
Mount Gretna weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJul 4Overcast46%—100°77°—
- SundayJul 5Heavy Rain91%0.83″93°71°-7°
- MondayJul 6Heavy Drizzle91%0.08″81°67°-12°
- TuesdayJul 7Light Showers67%—75°65°-6°
- WednesdayJul 8Light Drizzle12%0.03″82°64°+7°
- ThursdayJul 9Overcast32%—87°63°+5°
- FridayJul 10Light Drizzle39%—81°67°-6°
AQI 56 (Moderate), driven by PM2.5. AQI flat over the last 6 hours (within ±4 points). PM2.5 at 19.4 µg/m³ (AQI 70) with a 0.89 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 19.4 µg/m³ (AQI 70) with a 0.89 fine-to-coarse ratio and 6 mph wind — combustion smoke trapped in calm air, not road dust.
- PM2.5/PM10
- 0.89
- 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).
If the first of July be rainy weather, 'twill rain more or less for four weeks together.
- Moonrise
- 10:59 PM
- Moonset
- 10:09 AM
- In sign
- ♓︎ Pisces
Cicadas claim the afternoon
Mount Gretna at a glance
- Today vs. normal: 6°F above the seasonal normal for this latitude
- Last frost: April 17 (climatological average for this latitude)
- Microseason: Jul 1–5
- Planting window: Harvest early potatoes. Begin drying onions on the surface.
ZIP code: 17064
15-Day Forecast — Mount Gretna
- Sat100°77°46%
- Sun93°71°91%
- Mon81°67°91%
- Tue75°65°67%
- Wed82°64°12%
- Thu87°63°32%
- Fri81°67°39%
- Sat82°64°33%
- Sun85°66°28%
- Mon79°61°16%
- Tue84°70°14%
- Wed75°60°24%
- Thu82°57°26%
- Fri85°61°35%
- Sat71°66°42%
Forecast data from Open-Meteo (CC BY 4.0).
Right now in the garden
Peak growing season
As of July 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 — Mount Gretna
SPC has placed Mount Gretna in the Slight Risk category for severe thunderstorms today.
- TODAYSLGTSlight Risk
- TOMORROWSLGTSlight Risk
- DAY 3TSTMGeneral Thunderstorms
Scattered severe storms possible. A few tornadoes, hail, and damaging wind gusts possible.
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.
ZIP codes in Mount Gretna
- 17064