Waterbury, Connecticut Weather
Fireflies rise from the lawn. Day 77 of spring. Read this microseason across nine climate regions →
Waterbury weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 4Overcast——87°57°—
- FridayJun 5Overcast——91°62°+4°
- SaturdayJun 6Light Drizzle32%—89°64°-2°
- SundayJun 7Light Showers62%0.02″85°60°-4°
- MondayJun 8Light Drizzle19%0.02″78°53°-7°
- TuesdayJun 9Partly Cloudy——84°56°+6°
- WednesdayJun 10Mostly Clear——86°55°+2°
PM2.5 at 8.7 µg/m³ (AQI 48) with a 0.91 fine-to-coarse ratio and 3 mph wind — combustion smoke trapped in calm air, not road dust. AQI down 6 over the last 6 hours (steady decline since this morning).
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 30 now. With UV 3.3 peaking around 1 PM under clear skies, surface ozone likely climbs to AQI 13 by mid-afternoon.
- Present
- AQI 30
- UV peak
- 3.3 at 1 PM
- Sky at peak
- clear
- Projected peak
- AQI 13
PM × Wind × Precip
PM2.5 at 8.7 µg/m³ (AQI 48) with a 0.91 fine-to-coarse ratio and 3 mph wind — combustion smoke trapped in calm air, not road dust.
- PM2.5/PM10
- 0.91
- Wind
- calm
- 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).
A summer fog for fair, a winter fog for rain.
- Moonrise
- 3:25 AM
- Moonset
- 12:46 PM
- In sign
- ♑︎ Capricorn
Fireflies rise from the lawn
Waterbury at a glance
- Today vs. normal: 12°F below the seasonal normal for this latitude
- Last frost: April 25 (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.
Planting calendar
| Month | Plant | Harvest |
|---|---|---|
| January | — | — |
| February | — | — |
| March | — | — |
| April | lettuce, peas, spinach, radishes | — |
| May | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| June | tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| July | tomatoes, peppers, beans, squash | tomatoes, beans, summer squash |
| August | — | tomatoes, beans, summer squash |
| September | fall brassicas, garlic (overwinter), carrots | tomatoes, beans, summer squash |
| October | fall brassicas, garlic (overwinter), carrots | winter squash, tomatoes (last) |
| November | — | — |
| December | — | — |
A year in weather
July brings Waterbury's warmest temperatures (~73°F mean) while January delivers the coldest (~28°F). Rainfall reaches its peak in October (4.5 inches) and drops to its lowest point in February (2.9 inches).
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 28° | 3.0″ | 5 |
| February | 30° | 2.9″ | 5 |
| March | 38° | 4.0″ | 6 |
| April | 49° | 4.1″ | 7 |
| May | 59° | 3.5″ | 7 |
| June | 68° | 4.0″ | 7 |
| July | 73° | 3.4″ | 6 |
| August | 72° | 3.5″ | 6 |
| September | 65° | 4.3″ | 5 |
| October | 53° | 4.5″ | 6 |
| November | 42° | 3.4″ | 6 |
| December | 33° | 4.1″ | 7 |
Regional context
Waterbury belongs to a warm-summer humid continental climate region — sharing similar temperature ranges, seasonal patterns, and growing conditions with nearby cities.
Similar climates: Hartford, CT, Bridgeport, CT, New Haven, CT, Danbury, CT, Norwich, CT.
Naturalist notes
Red maple flowers emerge in late April, their crimson clusters appearing before the leaves unfurl.
American robins begin their dawn chorus in early May, marking the peak of spring migration.
Frequently asked
- When does it freeze in Waterbury?
- Waterbury's last spring frost typically occurs around mid-April, and the first fall frost arrives around mid-November.
- What is the rainy season in Waterbury?
- October receives the most rainfall with about 4.5 inches on average; the city gets roughly 45 inches annually.
- What is the warmest month in Waterbury?
- July typically brings the warmest weather, averaging about 73°F.
- What is the coldest month in Waterbury?
- January typically delivers the coldest temperatures, averaging about 28°F.
- When can I start a vegetable garden in Waterbury?
- Cool-season crops (peas, lettuce) can be planted around the last spring frost (mid-April); warm-season crops (tomatoes, peppers) should wait until 1–2 weeks after.
- How many rainy days does Waterbury get?
- Waterbury experiences about 74 rainy days per year on average.
- What hardiness zone is Waterbury?
- Waterbury's USDA hardiness zone depends on its lowest average winter temperature; check the USDA's online lookup with the city ZIP for the current zone designation.
Climate
Waterbury, Connecticut experiences a warm-summer humid continental climate zone. January temperatures hover near 28°F while July averages 73°F — a 45°F seasonal swing.
Throughout the year, Waterbury receives about 45 inches of precipitation spread over roughly 74 rainy days.
Latitude (41.6°N), proximity to large water bodies, and elevation set the rhythm of the year — shaping what grows here, when frost is likely, and what the weather story looks like day to day.