Cambridge, Massachusetts Weather
Fireflies rise from the lawn. Day 77 of spring. Read this microseason across nine climate regions →
Cambridge weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 4Overcast——91°60°—
- FridayJun 5Overcast——89°63°-2°
- SaturdayJun 6Heavy Showers32%1.0″93°64°+4°
- SundayJun 7Showers75%0.06″84°56°-9°
- MondayJun 8Heavy Drizzle28%0.09″64°52°-20°
- TuesdayJun 9Overcast——71°50°+7°
- WednesdayJun 10Clear——77°57°+6°
Ozone at AQI 98 now. AQI up 6 over the last 6 hours (gradual rise). With UV 8.0 peaking around 1 PM under clear skies, surface ozone likely climbs to AQI 105 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 98 now. With UV 8.0 peaking around 1 PM under clear skies, surface ozone likely climbs to AQI 105 by mid-afternoon.
- Present
- AQI 98
- UV peak
- 8.0 at 1 PM
- Sky at peak
- clear
- Projected peak
- AQI 105
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
Cambridge 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 — Cambridge
SPC has placed Cambridge 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.