Williamstown, Pennsylvania Weather
Cicadas claim the afternoon. Day 14 of summer. Read this microseason across nine climate regions →
Williamstown weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJul 4Light Drizzle38%—95°76°—
- SundayJul 5Light Showers60%0.07″91°73°-4°
- MondayJul 6Thunderstorm91%0.38″78°70°-13°
- TuesdayJul 7Light Showers81%0.01″81°64°+3°
- WednesdayJul 8Light Drizzle20%0.02″71°61°-10°
- ThursdayJul 9Light Drizzle15%—89°63°+18°
- FridayJul 10Light Drizzle59%0.02″81°66°-8°
AQI 85 (Moderate), driven by Ozone. AQI up 32 in the last 6 hours — air quality is degrading. Ozone at AQI 63 now. With UV 0.3 peaking around 1 PM under partly cloudy skies, surface ozone likely climbs to AQI 11 around 1 PM.
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 63 now. With UV 0.3 peaking around 1 PM under partly cloudy skies, surface ozone likely climbs to AQI 11 around 1 PM.
- Present
- AQI 63
- UV peak
- 0.3 at 1 PM
- Sky at peak
- partly cloudy
- Projected peak
- AQI 11
PM × Wind × Precip
PM2.5 at 4.9 µg/m³, PM10 at 5.1 µg/m³ — typical background levels with no transport signature.
- PM2.5/PM10
- 0.96
- Wind
- light
- 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
- 11:00 PM
- Moonset
- 10:09 AM
- In sign
- ♓︎ Pisces
Cicadas claim the afternoon
Williamstown at a glance
- Today vs. normal: 23°F above the seasonal normal for this latitude
- Last frost: April 19 (climatological average for this latitude)
- Microseason: Jul 1–5
- Planting window: Harvest early potatoes. Begin drying onions on the surface.
ZIP code: 17098
16-Day Forecast — Williamstown
- Sat95°76°38%
- Sun91°73°60%
- Mon78°70°91%
- Tue81°64°81%
- Wed71°61°20%
- Thu89°63°15%
- Fri81°66°59%
- Sat84°66°31%
- Sun78°61°26%
- Mon82°60°21%
- Tue82°60°18%
- Wed86°58°36%
- Thu87°60°48%
- Fri84°63°41%
- Sat87°66°40%
- Sun78°68°55%
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 — Williamstown
SPC has placed Williamstown 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 Williamstown
- 17098