Old Greenwich, Connecticut Weather
Fireflies rise from the lawn. Day 76 of spring. Read this microseason across nine climate regions →
Old Greenwich weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 3Clear——83°58°—
- ThursdayJun 4Overcast——86°59°+3°
- FridayJun 5Overcast——87°58°+1°
- SaturdayJun 6Overcast26%—91°70°+4°
- SundayJun 7Heavy Drizzle70%0.13″77°58°-14°
- MondayJun 8Light Drizzle45%0.01″76°53°-1°
- TuesdayJun 9Overcast15%—85°59°+9°
PM2.5 at 8.9 µg/m³ (AQI 49) with a 0.87 fine-to-coarse ratio and 5 mph wind — combustion smoke trapped in calm air, not road dust. AQI up 12 over the last 6 hours (gradual rise).
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 — peak already passed at 1 PM under clear skies. Levels should ease through evening.
- Present
- AQI 48
- UV peak
- 0.7 at earlier today
- Sky at peak
- clear
- Projected peak
- AQI 48
PM × Wind × Precip
PM2.5 at 8.9 µg/m³ (AQI 49) with a 0.87 fine-to-coarse ratio and 5 mph wind — combustion smoke trapped in calm air, not road dust.
- PM2.5/PM10
- 0.87
- 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
- 2:48 AM
- Moonset
- 11:46 AM
- In sign
- ♑︎ Capricorn
Fireflies rise from the lawn
Old Greenwich at a glance
- Today vs. normal: 6°F above the seasonal normal for this latitude
- Last frost: April 22 (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.
Beaches near Old Greenwich
- Jones Beach Beach29.9 mi
Each linked page shows live water temperature, wave height, swim and surf verdicts, tides, and rip-current risk from NDBC + NOAA + NWS data.