Palo Alto, Pennsylvania Weather
Fireflies rise from the lawn. Day 76 of spring. Read this microseason across nine climate regions →
Palo Alto weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 3Clear——78°51°—
- ThursdayJun 4Overcast——83°62°+5°
- FridayJun 5Overcast——82°62°-1°
- SaturdayJun 6Drizzle33%—86°63°+4°
- SundayJun 7Light Showers45%0.11″78°63°-8°
- MondayJun 8Overcast26%—75°55°-3°
- TuesdayJun 9Partly Cloudy15%—79°50°+4°
Ozone at AQI 48 now. AQI up 8 over the last 6 hours (gradual rise). With UV 7.5 peaking around 1 PM under clear skies, surface ozone likely climbs to AQI 48 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 48 now. With UV 7.5 peaking around 1 PM under clear skies, surface ozone likely climbs to AQI 48 by mid-afternoon.
- Present
- AQI 48
- UV peak
- 7.5 at 1 PM
- Sky at peak
- clear
- Projected peak
- AQI 48
PM × Wind × Precip
PM2.5 at 6.0 µg/m³ (AQI 33) with a 0.80 fine-to-coarse ratio and 6 mph wind — combustion smoke trapped in calm air, not road dust.
- PM2.5/PM10
- 0.80
- Wind
- light
- 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).
The higher the clouds, the finer the weather.
- Moonrise
- 2:57 AM
- Moonset
- 11:59 AM
- In sign
- ♑︎ Capricorn
Fireflies rise from the lawn
Palo Alto at a glance
- Today vs. normal: 76°F — typical for the season
- Last frost: April 20 (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.