Jamestown, Pennsylvania Weather
Fireflies rise from the lawn. Day 77 of spring. Read this microseason across nine climate regions →
Jamestown weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 4Overcast——78°54°—
- FridayJun 5Overcast——82°60°+4°
- SaturdayJun 6Overcast72%—80°59°-2°
- SundayJun 7Light Drizzle72%—79°62°-1°
- MondayJun 8Light Drizzle——79°58°0°
- TuesdayJun 9Mostly Clear——79°55°0°
- WednesdayJun 10Clear15%—83°55°+4°
PM2.5 at 13.2 µg/m³ (AQI 59) with a 0.96 fine-to-coarse ratio and 3 mph wind — combustion smoke trapped in calm air, not road dust. AQI down 8 over the last 6 hours (steady decline since this morning).
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 32. Overcast through the UV peak window (cloud cover ~62%) — afternoon ozone should stay flat.
- Present
- AQI 32
- UV peak
- 3.3 at 1 PM
- Sky at peak
- overcast
- Projected peak
- AQI 7
PM × Wind × Precip
PM2.5 at 13.2 µg/m³ (AQI 59) with a 0.96 fine-to-coarse ratio and 3 mph wind — combustion smoke trapped in calm air, not road dust.
- PM2.5/PM10
- 0.96
- 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
- 3:44 AM
- Moonset
- 1:13 PM
- In sign
- ♑︎ Capricorn
Fireflies rise from the lawn
Jamestown 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.