Somerville, Massachusetts Weather
Fireflies rise from the lawn. Day 77 of spring. Read this microseason across nine climate regions →
Somerville weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 4Overcast——91°59°—
- FridayJun 5Overcast——89°62°-2°
- SaturdayJun 6Heavy Showers32%1.0″92°64°+3°
- SundayJun 7Showers75%0.06″84°56°-8°
- MondayJun 8Heavy Drizzle28%0.09″64°52°-20°
- TuesdayJun 9Overcast——71°49°+7°
- WednesdayJun 10Clear——77°57°+6°
Ozone at AQI 500 now. AQI flat over the last 6 hours (within ±3 points). With UV 8.3 peaking around 1 PM under clear skies, surface ozone likely climbs to AQI 552 by mid-afternoon.
AVOID OUTDOORS Avoid outdoor exertion. Keep windows closed; use HEPA filtration indoors if available.
What's driving it
Ozone × UV × Sky
Ozone at AQI 500 now. With UV 8.3 peaking around 1 PM under clear skies, surface ozone likely climbs to AQI 552 by mid-afternoon.
- Present
- AQI 500
- UV peak
- 8.3 at 1 PM
- Sky at peak
- clear
- Projected peak
- AQI 552
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
- 3:20 AM
- Moonset
- 12:35 PM
- In sign
- ♒︎ Aquarius
Fireflies rise from the lawn
Somerville at a glance
- Today vs. normal: 17°F above the seasonal normal for this latitude
- Last frost: April 30 (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.
SPC Convective Outlook
Storm Prediction Center — Somerville
SPC has placed Somerville in the Marginal Risk category for severe thunderstorms day after tomorrow.
- TODAYNONENo severe risk
- TOMORROWNONENo severe risk
- DAY 3MRGLMarginal Risk
Isolated severe storms possible. Limited threat for hail or damaging wind.
Source: NOAA / NWS Storm Prediction Center categorical convective outlook. Outlooks are re-issued multiple times per day; this page reflects the most recent SPC polygons covering the city’s coordinates.