Mercersville, Maryland Weather
Cicadas claim the afternoon. Day 14 of summer. Read this microseason across nine climate regions →
Mercersville weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJul 4Overcast32%—102°76°—
- SundayJul 5Light Rain46%0.07″95°76°-7°
- MondayJul 6Light Drizzle79%0.01″81°71°-14°
- TuesdayJul 7Showers79%0.60″89°65°+8°
- WednesdayJul 8Light Drizzle24%—81°64°-8°
- ThursdayJul 9Overcast12%—94°65°+13°
- FridayJul 10Light Drizzle37%—89°68°-5°
AQI 93 (Moderate), driven by Ozone. AQI up 42 in the last 6 hours — air quality is degrading. Ozone at AQI 80. Overcast through the UV peak window (cloud cover ~100%) — afternoon ozone should stay flat.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion.
What's driving it
Ozone × UV × Sky
Ozone at AQI 80. Overcast through the UV peak window (cloud cover ~100%) — afternoon ozone should stay flat.
- Present
- AQI 80
- UV peak
- 0.4 at 1 PM
- Sky at peak
- overcast
- Projected peak
- AQI 10
PM × Wind × Precip
PM2.5 at 7.6 µg/m³, PM10 at 8.2 µg/m³ — typical background levels with no transport signature.
- PM2.5/PM10
- 0.93
- Wind
- breezy
- Recent rain
- 0h in last 6h
- Pattern
- background
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
- 11:04 PM
- Moonset
- 10:15 AM
- In sign
- ♓︎ Pisces
Cicadas claim the afternoon
Mercersville at a glance
- Today vs. normal: 16°F above the seasonal normal for this latitude
- Last frost: April 13 (climatological average for this latitude)
- Microseason: Jul 1–5
- Planting window: Harvest early potatoes. Begin drying onions on the surface.
16-Day Forecast — Mercersville
- Sat102°76°32%
- Sun95°76°46%
- Mon81°71°79%
- Tue89°65°79%
- Wed81°64°24%
- Thu94°65°12%
- Fri89°68°37%
- Sat91°68°30%
- Sun81°64°22%
- Mon84°64°17%
- Tue87°59°16%
- Wed89°61°39%
- Thu94°64°33%
- Fri84°67°33%
- Sat93°69°31%
- Sun86°69°37%
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 — Mercersville
SPC has placed Mercersville 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 Mercersville
- 21782