Williamstown, Pennsylvania Weather
Fireflies rise from the lawn. Day 76 of spring. Read this microseason across nine climate regions →
Williamstown weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 3Clear——79°51°—
- ThursdayJun 4Overcast——83°61°+4°
- FridayJun 5Overcast——83°65°0°
- SaturdayJun 6Heavy Drizzle39%—86°63°+3°
- SundayJun 7Light Showers41%0.09″79°62°-7°
- MondayJun 8Overcast12%—73°54°-6°
- TuesdayJun 9Partly Cloudy10%—77°49°+4°
Ozone at AQI 46 now. AQI up 14 over the last 6 hours (gradual rise). With UV 0.2 peaking around 1 PM under partly cloudy skies, surface ozone likely climbs to AQI 8 by mid-afternoon.
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 46 now. With UV 0.2 peaking around 1 PM under partly cloudy skies, surface ozone likely climbs to AQI 8 by mid-afternoon.
- Present
- AQI 46
- UV peak
- 0.2 at 1 PM
- Sky at peak
- partly cloudy
- Projected peak
- AQI 8
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
- 2:58 AM
- Moonset
- 12:01 PM
- In sign
- ♑︎ Capricorn
Fireflies rise from the lawn
Williamstown at a glance
- Today vs. normal: 3°F above the seasonal normal for this latitude
- Last frost: April 19 (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 3, 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.