Johnstown, Pennsylvania Weather
Fireflies rise from the lawn. Day 76 of spring. Read this microseason across nine climate regions →
Johnstown weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 3Clear——78°45°—
- ThursdayJun 4Overcast——82°53°+4°
- FridayJun 5Overcast——81°56°-1°
- SaturdayJun 6Drizzle63%—83°62°+2°
- SundayJun 7Showers63%0.02″75°62°-8°
- MondayJun 8Light Drizzle10%—73°57°-2°
- TuesdayJun 9Mostly Clear10%—80°52°+7°
Ozone at AQI 47 — peak already passed at 1 PM under clear skies. AQI up 11 over the last 6 hours (gradual rise). Levels should ease through evening.
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 47 — peak already passed at 1 PM under clear skies. Levels should ease through evening.
- Present
- AQI 47
- UV peak
- 4.2 at earlier today
- Sky at peak
- clear
- Projected peak
- AQI 47
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
- 3:07 AM
- Moonset
- 12:11 PM
- In sign
- ♑︎ Capricorn
Fireflies rise from the lawn
Johnstown at a glance
- Today vs. normal: 3°F above 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 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.